diff --git a/index.js b/index.js
index 64c8b6e..686b718 100644
--- a/index.js
+++ b/index.js
@@ -15,7 +15,7 @@ console.log('Day 1, Part 2:', day1Part2Answer);
 
 // TODO: Go back and redo days 2 & 3, for consistency :)
 
-/*
+/**
  * Day 4!
  * ----------------------------------
  */
@@ -28,7 +28,7 @@ var day4Part2Answer = Day4.adventCoinSecret(day4Input, '000000');
 console.log('Day 4, Part 1:', day4Part1Answer);
 console.log('Day 4, Part 2:', day4Part2Answer);
 
-/*
+/**
  * Day 5!
  * ----------------------------------
  */
@@ -78,4 +78,16 @@ day7Input.split('\n').forEach(function(instruction) {
   Day7.processInstruction(instruction);
 });
 
-console.log('Day 7, Part 1:', Day7.getWireSignal('a'));
+var signalA = Day7.getWireSignal('a');
+console.log('Day 7, Part 1:', signalA);
+
+Day7.resetWires();
+
+day7Input.split('\n').forEach(function(instruction) {
+  Day7.processInstruction(instruction);
+});
+
+Day7.setSignal('b', signalA);
+
+var newSignalA = Day7.getWireSignal('a');
+console.log('Day 7, Part 2:', newSignalA);
diff --git a/lib/day7.js b/lib/day7.js
index 11e363a..841a746 100644
--- a/lib/day7.js
+++ b/lib/day7.js
@@ -55,7 +55,13 @@ module.exports = {
     return wires[wire]();
   },
 
-  resetWires: function() { wires = {} }
+  setSignal: function(wire, signal) {
+    wires[wire] = function() { return signal };
+  },
+
+  resetWires: function() {
+    wires = {};
+  }
 
 };