diff --git a/src/IEngine.ts b/src/IEngine.ts
index a7938c696..d495e5e20 100644
--- a/src/IEngine.ts
+++ b/src/IEngine.ts
@@ -3,32 +3,25 @@
  * to TypeScript at the moment
  */
 export interface IEngine {
-  indexedDb: any;
   _lastUpdate: number;
-  hideAllContent: () => void;
-  loadTerminalContent: () => void;
-  loadScriptEditorContent: (filename?: string, code?: string) => void;
-  loadActiveScriptsContent: () => void;
-  loadCreateProgramContent: () => void;
-  loadCharacterContent: () => void;
-  loadFactionsContent: () => void;
-  loadAugmentationsContent: () => void;
-  loadHacknetNodesContent: () => void;
-  loadSleevesContent: () => void;
-  loadLocationContent: () => void;
-  loadTravelContent: () => void;
-  loadJobContent: () => void;
-  loadStockMarketContent: () => void;
-  loadBladeburnerContent: () => void;
-  loadCorporationContent: () => void;
-  loadGangContent: () => void;
-  loadMilestonesContent: () => void;
-  loadTutorialContent: () => void;
-  loadDevMenuContent: () => void;
-  loadFactionContent: () => void;
-  loadInfiltrationContent: (name: string, difficulty: number, maxLevel: number) => void;
-  loadMissionContent: () => void;
-  loadResleevingContent: () => void;
-  loadGameOptionsContent: () => void;
-  load: (save: string) => void;
+  updateGame: (numCycles?: number) => void;
+  Counters: {
+    [key: string]: number | undefined;
+    autoSaveCounter: number;
+    updateSkillLevelsCounter: number;
+    updateDisplays: number;
+    updateDisplaysLong: number;
+    updateActiveScriptsDisplay: number;
+    createProgramNotifications: number;
+    augmentationsNotifications: number;
+    checkFactionInvitations: number;
+    passiveFactionGrowth: number;
+    messages: number;
+    mechanicProcess: number;
+    contractGeneration: number;
+  };
+  decrementAllCounters: (numCycles?: number) => void;
+  checkCounters: () => void;
+  load: (saveString: string) => void;
+  start: () => void;
 }
diff --git a/src/Missions.d.ts b/src/Missions.d.ts
index 31c9a7777..8a1e7d522 100644
--- a/src/Missions.d.ts
+++ b/src/Missions.d.ts
@@ -2,5 +2,7 @@ export declare let inMission: boolean;
 export declare class HackingMission {
   constructor(reputation: number, faction: Faction);
   init(): void;
+  process(numCycles: number): void;
 }
 export declare function setInMission(inMission: boolean, mission: HackingMission): void;
+export declare let currMission: HackingMission;
diff --git a/src/PersonObjects/IPlayer.ts b/src/PersonObjects/IPlayer.ts
index c20a051e6..cbf0e6203 100644
--- a/src/PersonObjects/IPlayer.ts
+++ b/src/PersonObjects/IPlayer.ts
@@ -270,7 +270,7 @@ export interface IPlayer {
   createProgramWork(numCycles: number): boolean;
   takeClass(numCycles: number): boolean;
   commitCrime(numCycles: number): boolean;
-  checkForFactionInvitations(): void;
+  checkForFactionInvitations(): Faction[];
   setBitNodeNumber(n: number): void;
   getMult(name: string): number;
   setMult(name: string, mult: number): void;
diff --git a/src/PersonObjects/Player/PlayerObject.ts b/src/PersonObjects/Player/PlayerObject.ts
index 302664adf..717db70f1 100644
--- a/src/PersonObjects/Player/PlayerObject.ts
+++ b/src/PersonObjects/Player/PlayerObject.ts
@@ -277,7 +277,7 @@ export class PlayerObject implements IPlayer {
   createProgramWork: (numCycles: number) => boolean;
   takeClass: (numCycles: number) => boolean;
   commitCrime: (numCycles: number) => boolean;
-  checkForFactionInvitations: () => void;
+  checkForFactionInvitations: () => Faction[];
   setBitNodeNumber: (n: number) => void;
   getMult: (name: string) => number;
   setMult: (name: string, mult: number) => void;
diff --git a/src/PersonObjects/Player/PlayerObjectGeneralMethods.tsx b/src/PersonObjects/Player/PlayerObjectGeneralMethods.tsx
index 74fa37f3a..9ed815455 100644
--- a/src/PersonObjects/Player/PlayerObjectGeneralMethods.tsx
+++ b/src/PersonObjects/Player/PlayerObjectGeneralMethods.tsx
@@ -2015,8 +2015,8 @@ export function reapplyAllSourceFiles(this: IPlayer): void {
 //This function sets the requirements to join a Faction. It checks whether the Player meets
 //those requirements and will return an array of all factions that the Player should
 //receive an invitation to
-export function checkForFactionInvitations(this: IPlayer) {
-  let invitedFactions = []; //Array which will hold all Factions the player should be invited to
+export function checkForFactionInvitations(this: IPlayer): Faction[] {
+  let invitedFactions: Faction[] = []; //Array which will hold all Factions the player should be invited to
 
   var numAugmentations = this.augmentations.length;
 
diff --git a/src/Prestige.ts b/src/Prestige.ts
index 55a3920ca..be21e1352 100755
--- a/src/Prestige.ts
+++ b/src/Prestige.ts
@@ -85,8 +85,7 @@ function prestigeAugmentation(): void {
   }
 
   // Stop a Terminal action if there is onerror
-  if (Engine._actionInProgress) {
-    Engine._actionInProgress = false;
+  if (Terminal.action !== null) {
     Terminal.finishAction(Router, Player, true);
   }
 
@@ -195,8 +194,7 @@ function prestigeSourceFile(flume: boolean): void {
   }
 
   // Stop a Terminal action if there is one
-  if (Engine._actionInProgress) {
-    Engine._actionInProgress = false;
+  if (Terminal.action !== null) {
     Terminal.finishAction(Router, Player, true);
   }
 
diff --git a/src/engine.jsx b/src/engine.tsx
similarity index 92%
rename from src/engine.jsx
rename to src/engine.tsx
index 0008931c1..fe4213429 100644
--- a/src/engine.jsx
+++ b/src/engine.tsx
@@ -50,7 +50,29 @@ import { startUnclickable } from "./Exploits/unclickable";
 
 import React from "react";
 
-const Engine = {
+const Engine: {
+  _lastUpdate: number;
+  updateGame: (numCycles?: number) => void;
+  Counters: {
+    [key: string]: number | undefined;
+    autoSaveCounter: number;
+    updateSkillLevelsCounter: number;
+    updateDisplays: number;
+    updateDisplaysLong: number;
+    updateActiveScriptsDisplay: number;
+    createProgramNotifications: number;
+    augmentationsNotifications: number;
+    checkFactionInvitations: number;
+    passiveFactionGrowth: number;
+    messages: number;
+    mechanicProcess: number;
+    contractGeneration: number;
+  };
+  decrementAllCounters: (numCycles?: number) => void;
+  checkCounters: () => void;
+  load: (saveString: string) => void;
+  start: () => void;
+} = {
   // Time variables (milliseconds unix epoch time)
   _lastUpdate: new Date().getTime(),
 
@@ -106,7 +128,7 @@ const Engine = {
     }
 
     // Gang, if applicable
-    if (Player.inGang()) {
+    if (Player.inGang() && Player.gang !== null) {
       Player.gang.process(numCycles, Player);
     }
 
@@ -175,10 +197,10 @@ const Engine = {
   },
 
   decrementAllCounters: function (numCycles = 1) {
-    for (var counter in Engine.Counters) {
-      if (Engine.Counters.hasOwnProperty(counter)) {
-        Engine.Counters[counter] = Engine.Counters[counter] - numCycles;
-      }
+    for (const counterName in Engine.Counters) {
+      const counter = Engine.Counters[counterName];
+      if (counter === undefined) throw new Error("counter should not be undefined");
+      Engine.Counters[counterName] = counter - numCycles;
     }
   },
 
@@ -328,8 +350,9 @@ const Engine = {
       }
 
       // Gang progress for BitNode 2
-      if (Player.inGang()) {
-        Player.gang.process(numCyclesOffline, Player);
+      const gang = Player.gang;
+      if (Player.inGang() && gang !== null) {
+        gang.process(numCyclesOffline, Player);
       }
 
       // Corporation offline progress
diff --git a/utils/helpers/exceptionAlert.ts b/utils/helpers/exceptionAlert.ts
index 1c8ab60a6..8269ddd6a 100644
--- a/utils/helpers/exceptionAlert.ts
+++ b/utils/helpers/exceptionAlert.ts
@@ -5,17 +5,17 @@ interface IError {
   lineNumber?: number;
 }
 
-export function exceptionAlert(e: IError): void {
+export function exceptionAlert(e: IError | string): void {
   console.error(e);
   dialogBoxCreate(
     "Caught an exception: " +
       e +
       "<br><br>" +
       "Filename: " +
-      (e.fileName || "UNKNOWN FILE NAME") +
+      ((e as any).fileName || "UNKNOWN FILE NAME") +
       "<br><br>" +
       "Line Number: " +
-      (e.lineNumber || "UNKNOWN LINE NUMBER") +
+      ((e as any).lineNumber || "UNKNOWN LINE NUMBER") +
       "<br><br>" +
       "This is a bug, please report to game developer with this " +
       "message as well as details about how to reproduce the bug.<br><br>" +