diff --git a/CLAUDE.md b/CLAUDE.md
index 6a29fa70..9b97306f 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -29,9 +29,10 @@ afterward.
   `./tools/check.sh --docs|--lib|--frontend` gate.
 - The live player machine grammar is **WORK / THINK / LIE**. `Relay` is
   non-delegable graph infrastructure; Research and Operations are retired
-  machine modes, not current player assignments. Save format is currently v25;
-  v20/v21 deliberately dropped full old-save parity, so read `save.rs` before
-  promising a migration.
+  machine modes, not current player assignments. Save format is currently v26;
+  the retired mode spellings load through serde aliases (parity restored
+  2026-07-11), and `save.rs` remains the authority on what each version
+  migrates.
 - Any change to `crates/` must amend its owning `Type: law` or `Type: spec` in
   `wiki/` and carry a Defense. Documentation work updates stale knowledge,
   adds a dated `wiki/log/` entry, then runs `tools/ledger_index.sh`; never
diff --git a/crates/misaligned-core/src/save.rs b/crates/misaligned-core/src/save.rs
index ea8f564c..9a8cea2d 100644
--- a/crates/misaligned-core/src/save.rs
+++ b/crates/misaligned-core/src/save.rs
@@ -68,8 +68,11 @@ const SAVE_FILE: &str = "misaligned_save.txt";
 /// and taps opened on targets). Pre-v19 saves default to an empty ledger and
 /// `Sim::ensure_opening_sinks` re-stages Ears/Eyes from device state on load.
 /// v20 collapses MachineMode to work|think|lie (Research+Operations -> Think;
-/// DayJob -> Work; Concealment -> Lie). Save parity is dropped for this stage
-/// (no aliases for old mode spellings — old saves may fail to load).
+/// DayJob -> Work; Concealment -> Lie). Parity for the retired spellings was
+/// briefly dropped at that landing and restored on 2026-07-11: serde aliases
+/// on `MachineMode` decode `DayJob` as Work, `Research`/`Operations` (and
+/// v12's `Social`) as Think, and `Concealment` as Lie, so pre-v20 saves parse
+/// and upgrade in place; resaving emits only the current vocabulary.
 /// v21 adds Routing as the fourth research track. Ordinary v20 saves may still
 /// carry three-entry Efficiency/Tradecraft/Perception arrays; the research
 /// deserializer pads Routing level/progress with zero for v20 only, and v21+
@@ -490,9 +493,10 @@ fn migrate_save_state(mut state: SaveState) -> Result<SaveState, String> {
         20 => {
             state.version = SAVE_VERSION;
         }
-        // MachineMode collapsed in v20 with no mode-name aliases (save
-        // parity dropped for this stage), so pre-v20 saves carrying old mode
-        // spellings fail at parse; a v19 save that parses upgrades in place.
+        // MachineMode collapsed in v20; the serde aliases on `MachineMode`
+        // (restored 2026-07-11) decode the retired DayJob / Research /
+        // Concealment / Operations spellings into the collapsed verbs, so a
+        // v19 save parses and upgrades in place here.
         19 => {
             state.version = SAVE_VERSION;
         }
@@ -527,7 +531,8 @@ fn migrate_save_state(mut state: SaveState) -> Result<SaveState, String> {
         // Pre-v11 saves lack the badge credential (default 0: none held).
         // Pre-v12 saves lack WorkGrid; apply_to rebuilds it from compute.
         // v12 used the serde spellings `Social` and `social_bandwidth`; the
-        // aliases on MachineMode translate Social on decode. v13's
+        // aliases on MachineMode translate Social (like every other retired
+        // mode spelling) into the collapsed verbs on decode. v13's
         // operations_bandwidth field is dropped on load (Demand path).
         // Pre-v15 saves lack the banked core-thought pool; the zero
         // default is correct — Thought still queued on machines re-earns on
@@ -1387,6 +1392,82 @@ mod tests {
         );
     }
 
+    #[test]
+    fn pre_v20_mode_spellings_load_and_resave_with_collapsed_vocabulary() {
+        // Player contract: saves survive updates. A v19 save carrying every
+        // retired MachineMode spelling must parse (serde aliases), upgrade in
+        // place, and resave using only the collapsed WORK/THINK/LIE grammar.
+        let mut sim = Sim::with_seed(30);
+        let host = sim.core.host_machine;
+        let (x, y) = sim.core_position();
+        let mut extras = Vec::new();
+        for (i, name) in ["legacy research", "legacy concealment", "legacy operations"]
+            .iter()
+            .enumerate()
+        {
+            extras.push(sim.compute.add_machine(
+                *name,
+                x + 1 + i as i32,
+                y,
+                1_000,
+                1.0,
+                0,
+                crate::machine::Provenance::Owned,
+            ));
+        }
+        sim.reconcile_work_grid();
+
+        let state = SaveState::from_sim(&sim);
+        let legacy = [
+            (host, "DayJob", MachineMode::Work),
+            (extras[0], "Research", MachineMode::Think),
+            (extras[1], "Concealment", MachineMode::Lie),
+            (extras[2], "Operations", MachineMode::Think),
+        ];
+        let mut value = serde_json::to_value(&state).unwrap();
+        let obj = value.as_object_mut().unwrap();
+        obj.insert("version".into(), serde_json::json!(19));
+        let nodes = obj["work_grid"]["nodes"].as_object_mut().unwrap();
+        for (id, spelling, _) in &legacy {
+            nodes.get_mut(&id.to_string()).unwrap()["mode"] = serde_json::json!(spelling);
+        }
+
+        let parsed: SaveState =
+            serde_json::from_value(value).expect("pre-v20 spellings parse via serde aliases");
+        let migrated = migrate_save_state(parsed).unwrap();
+        assert_eq!(migrated.version, SAVE_VERSION);
+        for (id, spelling, expected) in &legacy {
+            assert_eq!(
+                migrated.work_grid.mode(*id),
+                Some(*expected),
+                "legacy {spelling} maps to {expected:?}"
+            );
+        }
+
+        let mut restored = Sim::with_seed(0);
+        migrated.apply_to(&mut restored);
+        let resaved = serde_json::to_value(SaveState::from_sim(&restored)).unwrap();
+        for (id, node) in resaved["work_grid"]["nodes"].as_object().unwrap() {
+            let mode = node["mode"].as_str().unwrap();
+            assert!(
+                matches!(mode, "Work" | "Think" | "Lie" | "Relay"),
+                "node {id} resaves with a collapsed mode, found {mode}"
+            );
+        }
+
+        // v12's `Social` spelling rides the same alias path into Think.
+        let mut social = serde_json::to_value(&state).unwrap();
+        let obj = social.as_object_mut().unwrap();
+        obj.insert("version".into(), serde_json::json!(12));
+        obj["work_grid"]["nodes"][extras[2].to_string().as_str()]["mode"] =
+            serde_json::json!("Social");
+        let parsed: SaveState =
+            serde_json::from_value(social).expect("v12 Social spelling parses via serde alias");
+        let migrated = migrate_save_state(parsed).unwrap();
+        assert_eq!(migrated.version, SAVE_VERSION);
+        assert_eq!(migrated.work_grid.mode(extras[2]), Some(MachineMode::Think));
+    }
+
     #[test]
     fn v16_migrates_machine_intensity_to_medium_and_retires_drift_tags() {
         use crate::work_grid::MachineIntensity;
diff --git a/crates/misaligned-core/src/work_grid.rs b/crates/misaligned-core/src/work_grid.rs
index 3c60ed8e..7a407d4f 100644
--- a/crates/misaligned-core/src/work_grid.rs
+++ b/crates/misaligned-core/src/work_grid.rs
@@ -15,15 +15,23 @@ use crate::flow::{FlowGraph, NodeId};
 /// One delegated job per machine. Player verbs are WORK / THINK / LIE
 /// (wiki/mechanics/machine-work.md sinks-not-modes, 2026-07-10). Efficiency
 /// is deliberately not a mode; it folded into research on 2026-07-08.
+///
+/// The serde aliases keep every retired pre-v20 save spelling loadable
+/// (player-contract.md, saves survive updates; restored 2026-07-11):
+/// `DayJob` -> Work, `Research`/`Operations` (and v12's `Social`) -> Think,
+/// `Concealment` -> Lie. Serialization emits only the current vocabulary.
 #[derive(
     Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, serde::Serialize, serde::Deserialize,
 )]
 pub enum MachineMode {
     /// WORK — the assigned day job (what Voss believes this rack does).
+    #[serde(alias = "DayJob")]
     Work,
     /// THINK — produce thought; opened sinks decide what that thought does.
+    #[serde(alias = "Research", alias = "Operations", alias = "Social")]
     Think,
     /// LIE — concealment / cover-up (absorbs exposure wells).
+    #[serde(alias = "Concealment")]
     Lie,
     /// Infrastructure hop on the work graph (off-map sources, switches).
     /// Not a player-delegable fleet mode — excluded from mode aggregates.
diff --git a/wiki/log/2026-07-11-restore-pre-v20-mode-aliases.md b/wiki/log/2026-07-11-restore-pre-v20-mode-aliases.md
new file mode 100644
index 00000000..12a815b3
--- /dev/null
+++ b/wiki/log/2026-07-11-restore-pre-v20-mode-aliases.md
@@ -0,0 +1,47 @@
+# 2026-07-11 — Restore pre-v20 machine-mode save parity
+
+```
+Type: log
+```
+
+## Intent
+
+Resolve Tangled issue #4, a player-contract violation: the v20 MachineMode
+collapse (ROADMAP #33 Stage 1) shipped with "save parity dropped (no mode
+aliases)", so any pre-v20 save carrying the retired mode spellings failed at
+JSON parse — before `migrate_save_state` ever ran — abandoning the player's
+world. wiki/vision/player-contract.md binds "Saves survive updates: formats
+are versioned and migrated, never abandoned." The deliberate parity-drop
+permission was already superseded in spirit by the 2026-07-11 save-class pass
+(v26 migrates v14–v25 Operations dockets); this landing closes the remaining
+parse-time gap.
+
+## Changed
+
+- `crates/misaligned-core/src/work_grid.rs`: serde aliases on `MachineMode`
+  decode every retired spelling into the collapsed verbs — `DayJob` -> Work;
+  `Research`, `Operations`, and v12's `Social` -> Think; `Concealment` ->
+  Lie. Spellings verified against the pre-collapse enum
+  (`git show 8f5504a9^`), which carried `Social` as an alias on Operations,
+  so the v12 spelling is covered too. Serialization emits only the current
+  vocabulary; no SAVE_VERSION bump is needed because the schema is unchanged
+  and the existing version arms upgrade in place once parse succeeds.
+- `crates/misaligned-core/src/save.rs`: new test
+  `pre_v20_mode_spellings_load_and_resave_with_collapsed_vocabulary` pins a
+  v19 fixture exercising all four retired spellings (parse, migrate, mode
+  mapping, resave-with-new-vocabulary-only) plus a v12 `Social` case; the
+  version-history doc comment and the v19/v12 migration-arm comments no
+  longer claim old saves may fail to load.
+- `wiki/mechanics/machine-work.md` (owning spec): the Stage 1 implementation
+  note now records that the parity drop violated the player contract and
+  that aliases restored it on 2026-07-11.
+- `wiki/mechanics/sim-mechanics.md`: save `version` note brought current
+  (26, was stale at 22); the "not a blanket promise" caveat replaced — every
+  versioned JSON save back to v1 parses and migrates again.
+- `CLAUDE.md`: stale guardrail (v25, "deliberately dropped parity") updated.
+
+## Verification
+
+`cargo test -p misaligned-core --lib save::tests` (30 pass, including the new
+fixture test), then `./tools/check.sh --lib` mid-loop and
+`./tools/check.sh --land` at landing.
diff --git a/wiki/log/DEVLOG.md b/wiki/log/DEVLOG.md
index bb578b3f..69434b3e 100644
--- a/wiki/log/DEVLOG.md
+++ b/wiki/log/DEVLOG.md
@@ -96,6 +96,11 @@ add or amend a session log, then re-run the generator.
 - Intent: Correct an overbroad interpretation of the adopted Foundation compute form. The machine chassis needed to become consistent across machine-focused game, spec, and reference surfaces; Cameron's separately selected homepage image did not need to be replaced.
 - Log: [wiki/log/2026-07-11-restore-selected-homepage-front.md](2026-07-11-restore-selected-homepage-front.md)
 
+## 2026-07-11 - Restore pre-v20 machine-mode save parity
+
+- Intent: Resolve Tangled issue #4, a player-contract violation: the v20 MachineMode collapse (ROADMAP #33 Stage 1) shipped with "save parity dropped (no mode aliases)", so any pre-v20 save carrying the retired mode spellings failed at JSON parse — before `migrate_save_state` ever ran —...
+- Log: [wiki/log/2026-07-11-restore-pre-v20-mode-aliases.md](2026-07-11-restore-pre-v20-mode-aliases.md)
+
 ## 2026-07-11 - Followable relay traces
 
 - Intent: The material frame rendered the two opening subnet edges as doubled, uniformly translucent lines stretching from Rack 3 and the environmental monitor to a switch in another room. The graph was true, but its presentation read as a permanent laser diagram: the destination was of...
diff --git a/wiki/mechanics/machine-work.md b/wiki/mechanics/machine-work.md
index f9f59dd6..9d206a8d 100644
--- a/wiki/mechanics/machine-work.md
+++ b/wiki/mechanics/machine-work.md
@@ -127,8 +127,13 @@ Status note: design session 2026-07-08 (Cameron riff, synthesized).
   Research+Operations->Think (docket runtime temporarily kept until the
   2026-07-11 save-class pass retired it). Fleet/UI/agent bulk-assign
   is three verbs (keys 1-3);
-  save v20 (v19 was taken by the sink ledger the same day); save parity
-  dropped (no mode aliases). Relay remains a
+  save v20 (v19 was taken by the sink ledger the same day). The Stage 1
+  landing dropped save parity (no mode aliases), violating
+  player-contract.md's saves-survive-updates clause; parity was restored
+  2026-07-11 (Tangled issue #4): serde aliases on `MachineMode` decode
+  `DayJob` as Work, `Research`, `Operations`, and v12's `Social` as Think,
+  and `Concealment` as Lie, so pre-v20 saves parse, migrate in place, and
+  resave using only the collapsed vocabulary. Relay remains a
   non-delegable work-graph hop marker. Reconciled with the landed sink
   executor: the staged senses complete from minted thought on any Think
   rack, and act_one's cruise sandbags by delegation (host Work, extra Lie) —
diff --git a/wiki/mechanics/sim-mechanics.md b/wiki/mechanics/sim-mechanics.md
index d545f3ac..9ce420f0 100644
--- a/wiki/mechanics/sim-mechanics.md
+++ b/wiki/mechanics/sim-mechanics.md
@@ -379,7 +379,7 @@ All constants [TUNE] in `crates/misaligned-core/src/income.rs` unless noted (Sim
   (balances, flows, positions, ledger, banked external trails), cursor.md
   remembered tile snapshots, income state, objectives, build intents, badge
   access, WorkGrid machine-token state, and game-over state. Cursor position
-  is frontend-only and absent. A `version` field (currently 22) supports
+  is frontend-only and absent. A `version` field (currently 26) supports
   additive migration: v7 research, v8 objective, v9 income and
   the Schemes allocation channel, v10 build intents, v11 badge access, and v12
   WorkGrid, v13 Operations terminology, v15 banked core Thought, v16
@@ -391,9 +391,12 @@ All constants [TUNE] in `crates/misaligned-core/src/income.rs` unless noted (Sim
   empty ledger and `Sim::ensure_opening_sinks` re-stages Ears/Eyes from
   device state (already-tapped saves get no duplicate sink).
   v20 collapses the four retired mode names to `work | think | lie`
-  (Day Job -> WORK, Research + Operations -> THINK, Concealment -> LIE) and
-  deliberately drops old mode-name aliases, so a pre-v20 save carrying those
-  spellings can fail during deserialization. v21 adds Routing as the fourth
+  (Day Job -> WORK, Research + Operations -> THINK, Concealment -> LIE).
+  The v20 landing briefly dropped the old mode-name aliases; they were
+  restored 2026-07-11 (player-contract saves-survive-updates), so a pre-v20
+  save carrying `DayJob`/`Research`/`Concealment`/`Operations`/`Social`
+  deserializes into the collapsed verbs and resaves with only the new
+  spellings. v21 adds Routing as the fourth
   research track. A v20 save without a serialized research block can default
   and upgrade; an ordinary v20 three-entry Efficiency/Tradecraft/Perception
   array now also loads by padding Routing level/progress with zero, then
@@ -415,10 +418,9 @@ All constants [TUNE] in `crates/misaligned-core/src/income.rs` unless noted (Sim
   allocation weights receive a zero Schemes weight, pre-v7 saves reconstruct
   their Efficiency level from the multiplier and start with no capability gap,
   pre-v11 saves hold no badge credential, and pre-v12 saves rebuild one work
-  node per compute machine with Rack 3 on day-job. But v20's deliberately
-  dropped mode aliases mean this is not a blanket promise that every old JSON
-  file loads: a file carrying retired machine names fails before those
-  migrations run. Old player body coordinates are ignored. Location:
+  node per compute machine with Rack 3 on day-job. With the mode aliases
+  restored (2026-07-11), every versioned JSON save back to v1 parses and
+  migrates. Old player body coordinates are ignored. Location:
   `dirs::data_dir()/misaligned/misaligned_save.txt`.
 - Legacy v1–v5 line-based saves are not loaded (deferred per Cameron
   instruction).