This guide explains how to complete the Big Mouse Little Hope final mission in Mouse: P.I. for Hire, including how to defeat Soyer and find every collectible location in the level. This final mission revisits Der Harzerburg from the prologue, but features new objectives and collectibles. If you’re stuck progressing, this walkthrough covers all steps along the way.
After completing the Fair Enough mission, you should have 36 Newspapers, 41 Baseball Cards, and 28 Comic Books. If you don’t, you may want to go back to an old save to avoid missing 100% completion.
You must also be very careful to collect every Big Mouse Little Hope final mission collectible, as you will not have the opportunity to purchase any you miss.

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How to Complete Big Mouse Little Hope Final Mission in Mouse: P.I. for Hire
Key Objectives
Chase after Soyer.
Survive the BMP onslaught.
Defeat Soyer.
Best Route to Get All Collectibles in Big Mouse Little Hope Final Mission
To collect every item in a single run, make sure to fully clear each area before progressing forward. Several sections in the Big Mouse Little Hope final mission lock behind you once you advance, especially when passing through doorways that close.
In particular:
Grab the first Comic Book before you jump off the big ledge early in the level.
Collect the first Newspaper and Schematic in the room with the vault door before you enter the casino.
Pick up the final Newspaper and two Schematics before you approach the locked door you must tailpick.
Following this order will prevent you from missing any items, needing to reload an earlier save, or restarting the level for 100% completion.
If you’re looking for step-by-step instructions, jump to the full walkthrough below.
Core Rule for Big Mouse Little Hope Final Mission Collectibles
The Big Mouse Little Hope final mission is built around one-way progression, so the goal is to collect everything before each point of no return.
Any time you are about to pass through a door or trigger a sequence, assume the area behind you is about to lock. If you have not cleared the current area, do not move forward yet. Missing even one of these points will require reloading a previous save to complete the level at 100%.
All Big Mouse Little Hope Final Mission Collectibles
There are six collectibles in the Big Mouse Little Hope final mission, including Comic Books, Newspapers, and Schematics. The list below shows a full breakdown.
Collectible
Location
Comic Book #1
In front of a Warp Pipe. After climbing the ladder early in the level, shoot the target to the right and complete the parkour section.
Newspaper #1
Under a crate in the room with the vault door before the casino.
Schematic #1
Inside the customer service booth in the room with the vault door before the casino.
Newspaper #2
In an alcove on the stairwell after the crate-filled corridor.
Schematic #2
Up a ladder in the stairwell after Soyer goes down in the elevator.
Schematic #3
In a safe before a door you must tailpick.
Big Mouse Little Hope Final Mission Walkthrough (All Der Harzerburg Collectibles)
It’s easy to miss collectibles if you follow the objective markers too quickly. Use the steps below to complete the Big Mouse Little Hope final mission without missing any items. For help with other missions, see our 100% Mouse P.I. for Hire collectibles guide.
Go After Soyer
Head down the stairs and into the elevator. Flip the switch to catch a ride, and follow your Detective’s Brush through a door and up a ladder.
Do not drop off the ledge at the end of the walkway. That is a point of no return, and you will miss a Comic Book if you drop immediately. If you have already jumped from the ledge, you’ll need to reload an old save if you want to get the collectible.
Comic Book
Instead of going to the ledge, you should look over the banister on your right. Shoot the target across the room to lower two Grapple Tail points, and use them to cross to the other side.
Now use the Wall Jump platforms to approach the large fan and shoot the target behind it to stop the blades. Enter the area behind the fan and look on the ground in front of the Warp Pipe to find a Comic Book. This is the final Comic Book in the game, so make sure to grab it now. You will earn The Prequel achievement when you collect the item.
Once you’ve triggered the achievement, go through the Warp Pipe and ride the lift to a room with a typewriter. There is a safe in the room, but you don’t need to open it, as it only holds cash.
After making a save, head into the next room, where you’ll find a locked vault door. Just like in the Big Mouse Little Hope prologue, you’ll open that door by flipping a switch in the customer service booth in the center of the room.
Do not go through the vault door yet, as it will lock behind you, and there are a couple of collectibles in this room to grab first. If you have gone through the vault door without getting the collectibles, you’ll need to reload an old save.
Newspaper
There’s a single crate on the west side of the room. Break it to reveal a Newspaper.
Schematic
There is a Schematic inside the customer service booth, in the section without the switch. Break through the glass window to access it.
Once you’ve grabbed both collectibles in the room and opened the vault door, head into the casino. The door will close behind you, and you cannot go back to any of the previous areas.
Newspaper
Beat all the enemies inside the casino and follow your Detective’s Brush into the corridor filled with crates. At the end of this sequence, you climb a small flight of stairs. Look right at the top to find the game’s final Newspaper on the ground, which you must collect now, as another lock-out point is coming up. You’ll earn the Extra Extra achievement when you grab that collectible.
Schematic
Now keep following the main path until you see Soyer in an elevator. Head down the stairs, and climb the ladder in the stairwell to grab a Schematic.
Schematic
Head through the door at the bottom of the stairs, and look left when you reach the barrels that block your path to find a safe. Tailpick it to get the game’s final Schematic.
Do not break through the barrels yet, as this will trap you. First, confirm that you’ve collected the previous Newspaper and two Schematics. If you’ve missed one of those collectibles and passed the barrels, you’ll need to reload an old save.
Once you’re through the barrels, tailpick the locked door, make a save in the next room, and head to the exterior area where Jack fell during the prologue. You will fall again, but Tammy will catch you this time, and a new sequence will begin.
Survive the BMP Onslaught
This sequence, which centers around jumping across planes and destroying planes and their bombs, can be annoying, as you’ll be forced to restart it if you fall. The most common mistakes here are going too fast and not destroying the incoming bombs, which will try to push you off the planes.
Really take your time with this sequence, focusing on precise jumps and prioritizing shooting bombs before they hit you. Eventually you’ll reach the final plane and leave the sky.
Pick Up the Chase
Follow the path through the vault doors to reach a room with a typewriter and lots of ammo. Make sure to stock up, as you are just about to start the final boss fight.
Before you pass through the door into the boss arena, use the B.A.N.G. on the ground by the door to finish any weapon upgrades. This is your last chance to upgrade every weapon to tier 3 and earn the We’ll B.A.N.G. OK achievement, as there’s no going back once you engage the boss. Fortunately, you can always just reload a save and perform the upgrades if you miss this opportunity.
How to Defeat Milford Soyer
The name of the game here is survival, as the fight starts with a long sequence where you cannot damage Soyer. During this sequence, focus on quickly destroying the mouth enemies on the walls, avoiding the targets that appear on the floor, and dodging lasers. Luckily, there are lots of health refills and armor pickups along the perimeter of the arena, which you can grab when the lasers are not active.
Eventually, the survival sequence will end, and you’ll do battle with Soyer’s bodyguard. You have unlimited ammo here, so pull out your Loose Cannon and start blasting. Also, make sure to keep an eye on the ground, as the lesser enemies will drop cheese that you can use to replenish some health.
When the bodyguard is defeated, you can finally start attacking Soyer on his platform. You’ll still have unlimited ammo, so keep holding down the trigger with the Loose Cannon equipped to deal big damage. Don’t ignore the rockets Soyer shoots, though. It’s a common mistake to only focus on hitting the boss, and the rockets can easily kill Jack and send him back to the bodyguard fight.
Release John
When Soyer’s health hits zero, talk to him, and then interact with John, who will be hanging from a rope to your left. Talk to John when he hits the ground to complete the Big Mouse Little Hope final mission, trigger the final cutscene, and beat the game.
Missable Collectibles & Common Mistakes
The biggest mistake in the Big Mouse Little Hope final mission is following objective markers before fully clearing the current area.
This level is not especially difficult, but it is very linear. Most missed collectibles happen because players assume they can backtrack after a door or scripted sequence. In many cases, they cannot.
Before jumping off the big ledge early in the level: grab Comic Book #1.
Before entering the casino: grab Newspaper #1 and Schematic #1
Before approaching the tailpick door: grab Newspaper #2 and Schematics #2 & #3.
If you remember one rule, make it this: clear the current area before committing to the next doorway or scripted sequence.
FAQ
How many collectibles are on Der Harzerburg?
There are six collectibles in the Big Mouse Little Hope final mission: one Comic Book, two Newspapers, and three Schematics.
Are Der Harzerburg collectibles missable?
After completing the Big Mouse Little Hope final mission, you cannot return to Der Harzerburg for any collectibles you missed. If you are going for 100% completion, make sure to get everything along the way.
More Mouse P.I. for Hire Collectible Guides

Released
April 16, 2026
Developer(s)
Fumi Games
Publisher(s)
PlaySide
Engine
Unity
Number of Players
Single-player


