Overview

Deep Clue Sea revolves around the Investigate mechanic introduced in Shadows over Innistrad and expanded significantly in Karlov Manor. Morska, Undersea Sleuth removes your maximum hand size, auto-investigates every upkeep for a steady trickle of Clues, and grows two +1/+1 counters bigger whenever you draw your second card in a turn — so the deck wants you cracking Clues and casting draw spells to keep hitting that threshold, with no downside to hoarding whatever Clues you don't need yet.

The supporting cast compounds this advantage through artifact token synergies. Academy Manufactor multiplies every Clue produced into a Clue, Food, and Treasure simultaneously. Lonis, Cryptozoologist generates Clues whenever creatures enter the battlefield, then sacrifices them to steal a cheap nonland permanent straight out of an opponent's library and onto your own battlefield. The deck's strategy is to establish an overwhelming token economy, convert tokens into cards faster than opponents can answer threats, and eventually overwhelm the table with the creatures and value generated along the way.

Key Cards

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Academy Manufactor
Token Multiplier · Artifact Engine
Whenever you would create a Clue, Food, or Treasure token, you instead create one of each. In a deck built around Investigate, Academy Manufactor is the single most backbreaking card: every Clue you make becomes a Clue, Food, and Treasure simultaneously. This triples the value of every Investigate trigger on the board, generating mana through Treasures, life through Food, and card draw through Clues at once. The token count becomes overwhelming within a few turns of Manufactor entering play.
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Lonis, Cryptozoologist
Clue Generator · Board Control
Whenever a non-token creature enters the battlefield under your control, you Investigate. Tap and sacrifice X Clues, and a target opponent reveals the top X cards of their library — you may put a nonland permanent with mana value X or less from among them onto the battlefield under your control, no mana cost paid. Lonis turns every creature you play into a Clue and then turns those Clues into free permanents stolen straight out of an opponent's own library.
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Tireless Tracker
Clue Generator · Growth
Landfall: whenever a land you control enters, investigate. Whenever you sacrifice a Clue, it gets a +1/+1 counter. In a deck that makes Clues constantly, every Clue you crack makes it bigger while it draws you a card.
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Ongoing Investigation
Clue Generator · Enchantment
Whenever one or more creatures you control deal combat damage to a player, investigate. For {1}{G}, you can also exile a creature card from your graveyard to investigate and gain 2 life, so a spent creature still pays you back with a Clue.

Playing the Deck

The first priority is establishing the Clue-generation engine. Morska coming down on turn four or five alongside any creature that Investigates on ETB creates an immediate card advantage surge. Lonis, Cryptozoologist in the early turns converts every subsequent creature play into a free Clue, building up a stock of tokens to fuel its own ability and, later, Academy Manufactor's multiplied output.

The mid game is defined by finding and protecting Academy Manufactor. Once it hits the table, every Investigate trigger produces three tokens: the raw mana from Treasures lets the deck accelerate past its land count, the Food buys life points, and the sheer number of Clues stacking up gives Lonis a deep well to draw on. Tireless Tracker grows every time you sacrifice a Clue, and Ongoing Investigation adds more Clues whenever your creatures connect.

The late game is about converting the overwhelming token economy into a board presence. Sacrifice outlets that convert Clues and Treasures into damage or creature tokens translate the card draw into a winning position. The deck's Bant colours provide sufficient removal to answer threats that slip through, and the sheer volume of cards drawn ensures that answers and threats arrive consistently every turn.

Strengths & Weaknesses

Strengths: Deep Clue Sea generates card advantage at a rate few precons can match. Morska's no-maximum-hand-size and free upkeep Investigate mean the deck never runs out of resources to work with, and Academy Manufactor multiplies the token count exponentially. The deck is resilient to single-target removal because the Clue engine regenerates value even after losing individual pieces.

Weaknesses: The deck's power is heavily concentrated in Academy Manufactor — without it the token economy is good rather than exceptional. Mass enchantment removal hits Morska and several key permanents simultaneously. The Bant colours lack the targeted discard or stax effects that would let the deck fully exploit its card advantage lead.

Want to improve it? See the Deep Clue Sea upgrade guide: ten cheap swaps with the data behind each one.

Verdict
Deep Clue Sea is one of the most mechanically cohesive precons from Murders at Karlov Manor Commander. Morska rewards drawing multiple cards a turn rather than just hoarding Clues passively, turning Investigate from a minor card advantage tool into a real growth engine, and cards like Academy Manufactor and Lonis give the deck genuine competitive infrastructure. Players who enjoy generating incremental value and converting token economies into wins will find the deck deeply satisfying to pilot. The upgrade ceiling is high: adding more Investigate triggers and sacrifice payoffs quickly pushes the deck into highly competitive territory.

Want to build a fully optimised investigation upgrade? Let the Oracle find the best Clue synergies.

✦ Build with The Oracle

Frequently Asked Questions

What cards are in the Deep Clue Sea decklist?
The Deep Clue Sea precon is a 100-card Commander deck led by Morska, Undersea Sleuth. The full Deep Clue Sea decklist, with every card, current prices and a button to copy the list into your deck builder, is on this page.

Who is the commander of Deep Clue Sea?
Deep Clue Sea is led by Morska, Undersea Sleuth, a white, blue and green commander.

Which set is Deep Clue Sea from?
Deep Clue Sea was released in 2024 as part of Murders at Karlov Manor Commander.

How can I upgrade Deep Clue Sea?
We have a step-by-step upgrade guide for Deep Clue Sea that lists specific cards to cut and add, with the reason for each swap.

Full Decklist

All 100 cards from the out-of-the-box Deep Clue Sea precon, enriched with current prices. Click any card to expand it.

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