Deep Clue Sea is the Bant investigation precon from Murders at Karlov Manor Commander, led by Morska, Undersea Sleuth. It generates Clue tokens at an extraordinary rate through the Investigate mechanic, then converts that token economy into card draw, creature tokens, and a board state that snowballs out of control once the artifact synergies come online.
May 2026Precon GuideBant · W/U/G
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Face Commander · MKC · Rare · Legendary Creature
Morska, Undersea Sleuth
Legendary Creature — Merfolk Detective
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W/U/G · BantInvestigateClue TokensKarlov Manor
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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Tamiyo's Journal
Clue Producer · Tutor Engine
An Artifact that Investigates at the start of your upkeep and can be sacrificed alongside three Clues to tutor any card from your library into your hand. Tamiyo's Journal provides automatic Clue generation every turn and a built-in tutor that costs no mana once you have the Clues in play. In a deck that already generates Clues prolifically through creatures and spells, finding the three required Clues is trivial, making Journal a repeatable search effect that can find Academy Manufactor, Morska, or any other silver bullet you need.
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Bruvac the Grandiloquent
Mill Amplifier · Alternate Win Con
Whenever an opponent would mill cards, they mill twice that many instead. Deep Clue Sea isn't built as a dedicated mill deck, but the incidental mill effects it does run go twice as far with Bruvac in play, and against a table already worn down by the deck's relentless card advantage, doubled mill can be enough to close a game few other cards in the precon are built to end outright.
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. Tamiyo's Journal finds missing pieces during this phase, and the Clue stockpile it requires accumulates quickly when Manufactor is in play.
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.
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 the reprints (Academy Manufactor, Lonis, Tamiyo's Journal) 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.