Marcus Quest Abyss Guide, How to Complete it All!

Abyss has several hidden quest lines that are easy to miss, and the Marcus quest chain is one of the most important for long-term progression. Marcus is not located near beginner safe zones, so reaching him already feels like a challenge.

Still, finishing his full set of quests unlocks new story content and leads directly to another key NPC quest line. This guide breaks down how to reach Marcus and how to complete all six of his quests efficiently.  Also check out Roblox Abyss Codes for more rewards.

How to Find Marcus in Ancient Sands

Marcus is located in the Ancient Sands area, far from oxygen-safe zones. Before traveling there, prepare multiple oxygen pods. The dive is longer than most early-game routes, and running out of oxygen will force you to restart the trip.

Bring extra inventory space as well, since several quests require collecting multiple fish and items in one run. Planning your route and gathering materials in batches will save a lot of time.

1. Marcus Quest 1 Requirements and Rewards

The first quest is simple and works as an introduction to the area.

Requirements:

• Catch 1 Sand Mutated Fish
• Catch 6 Pompano

Rewards:

• 1,000 cash
• 1 small oxygen pod
• 5 star shards

Focus on learning the spawn spots of Sand Mutated Fish early, since they appear again in later quests.

2. Marcus Quest 2 Requirements and Rewards

The second quest expands your farming targets.

Requirements:

• Bring 1 Fish Bone
• Catch 6 Cod
• Catch 2 Sand Mutated Fish

Rewards:

• 1,600 cash
• 2 small oxygen pods
• 5 star shards

Fish Bones can drop while farming other targets, so keep extras if possible.

3. Marcus Quest 3 Requirements and Rewards

Quest three introduces rarer catches.

Requirements:

• Catch 1 Cactus Mutated Fish
• Catch 4 Cod
• Catch 3 Blackfin Tuna
• Catch 5 Pompano

Rewards:

• 1 Cactus Geode
• 10 star shards
• 3,850 cash
• 1 basic oxygen pod

Blackfin Tuna and Cactus Mutated Fish may take longer to find, so expect some grinding here.

4. Marcus Quest 4 Requirements and Rewards

This quest mixes fishing with treasure hunting.

Requirements:

• Bring 2 Fish Bones
• Open 10 Tier 1 Treasure Chests
• Catch 6 Blackfin Tuna
• Catch 3 Sand Mutated Fish
• Catch 6 Pompano
• Crack 3 Cactus Geodes

Rewards:

• 10 star shards
• 1 speed potion
• 3,850 cash
• 1 basic oxygen pod

Try to combine chest hunting with fishing routes to reduce travel time.

5. Marcus Quest 5 Requirements and Rewards

Quest five raises the difficulty again.

Requirements:

• Find 2 Tier 2 Treasure Chests
• Catch 4 Grouper
• Catch 6 Cod
• Catch 2 Fossil Mutated Fish
• Catch 5 Blackfin Tuna

Rewards:

• 15 star shards
• 1 drop luck potion
• 4,450 cash
• 4 small oxygen pods

The drop luck potion can help with future farming, so this quest is especially valuable.

6. Marcus Quest 6 Requirements and Final Rewards

The final quest is the longest and acts as the climax of the chain.

Requirements:

• Bring 6 Fish Bones
• Catch 6 Blackfin Tuna
• Catch 4 Scorpion Fish
• Catch 5 Grouper
• Catch 2 Fossil Mutated Fish
• Catch 3 Cactus Mutated Fish
• Crack 5 Cactus Geodes

Rewards:

• Burger
• 7,800 cash
• 1 XP potion
• 1 Cactus Geode
• 15 star shards
• 4 basic oxygen pods

The Burger is the key reward. Giving it to Grumpy Hank completes Marcus’s storyline and unlocks a new NPC quest chain.

The Marcus quest line in Abyss takes time and preparation, but the rewards and progression it unlocks make it one of the most important side stories in the game. By stocking enough oxygen, farming materials in batches, and planning efficient routes through Ancient Sands, you can complete all six quests without unnecessary backtracking. Finishing this chain sets you up for the next stage of progression and opens the door to even more advanced content.