Marathon: Return on Investment 2 Guide – Acquiring Explosives and Dealing Damage

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The “Return on Investment 2” contract in Marathon tasks you with infiltrating a secure building close to the Maintenance area to steal explosives. You’ll then use these explosives against enemies. This mission, part of the Traxus priority contracts, is relatively straightforward if you’re skilled with explosives. This Marathon guide will show you where to find the explosives and how to maximize explosive damage in a single round.

How to Complete Return on Investment 2 in Marathon

Acquire Explosive Supplies

To get the explosives, go to the southwestern part of Maintenance on Dire Marsh. Look for a small building painted white and red that’s connected to a raised walkway. If you see green lasers shining on all the windows, you’ve found the right place. Walk up to the building, but don’t try to enter it yet.

Those green lasers aren’t just for show – they’re security sensors. If you break the beams, an alarm will sound and the doors will lock, trapping you inside. This could attract unwanted attention from the UESC and Runners nearby, and to make things worse, the building is full of active claymore mines. Panicking and making a mistake could be fatal.

Luckily, there’s a safe way to get inside. Look through the windows until you find the security boxes sticking out from the walls – there are two, one on each floor. They both have a noticeable red light. Shoot and destroy both boxes to turn off the security system, letting you enter without being detected. And remember to be careful of any claymores on the floor.

Okay, so I found this yellow and orange container upstairs, and it had some grenades inside – sweet! Now I just need to find someone – or something – to blow up with them. Time to cause some explosive mayhem!

Deal 750 Explosive Damage

Now, you need to inflict explosive damage on either UESC robots or enemy Runners. Although you can target Runners, it’s simpler and more effective to focus on the UESC robots.

The fastest way to deal a lot of damage quickly is to find groups of UESC robots close together. These groups can form naturally, like when UESC dropships arrive, or you can create them yourself by triggering certain events. Here are some ways to make UESC robots gather closely together:

  • Guarded Exfils
  • Container Hacks
  • Proximity Sensors (usually found in Maintenance)

You’re not restricted to just the explosives in the supply box. Feel free to use any other grenades you have or find to complete the objective.

Good news – you don’t have to finish Return on Investment 2 in one go! Any explosive damage you deal will stick with you for your next attempt if you don’t succeed right away. While you’re preparing to leave, check out our interactive map of Dire Marsh to find the best places to gather loot if you have inventory space.

All Rewards for Completing Return on Investment 2

Because this is a high-priority contract, completing Return on Investment 2 will give you significant rewards. You’ll earn 420 Traxus reputation points, plus the following benefits:

  • Deluxe Bully SMG
  • (70) Heavy Ammo
  • (1) Random Enhanced Grip Mod
  • (2) Random Enhanced Salvage
  • 2,000 Credits

Want to find the best guns in Marathon? Our tier list will help you choose the most effective weapons on Tau Ceti IV.

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2026-03-27 23:38