Which playing card replaces the question mark?

In a snake-path (boustrophedon) matrix grid, each attribute of the figures can follow its own independent traversal order across the cells — one attribute may snake row by row while a different attribute snakes column by column, each with its own fixed rule of change. The missing cell is found by continuing each attribute's own path independently to that cell's position, not by reading the grid in only one direction.

Value sequence (row-wise snake: row 1 left→right, row 2 right→left, row 3 left→right; each step is +4, wrapping after King back to Ace, i.e. Ace=1 … King=13):

1. Row 1 runs A♥(1) → 5♣(5) → 9♦(9) → K♠(13) → 4♥(4) → 8♣(8), each exactly 4 more than the last.

2. Row 2 (read right to left) continues the same +4 step: Q♥(12) → 3♣(3, since 12+4=16 wraps to 3) → 7♦(7).

3. The missing card is the next cell in this same path: 7+4 = 11, which is a Jack.

4. Continuing past the gap still holds: 2♥(11+4=15 wraps to 2) → 6♣(6), matching the printed cards.

Suit sequence (column-wise snake: column 1 top→bottom, column 2 bottom→top, column 3 top→bottom, …, cycling Hearts → Clubs → Diamonds → Spades → Hearts …):

1. Column 1 (top→bottom): A♥(Hearts) → 6♣(Clubs) → 10♦(Diamonds).

2. Column 2 (bottom→top): A♠(Spades) → 2♥(Hearts) → 5♣(Clubs).

3. Column 3 (top→bottom) begins with 9♦(Diamonds); the next suit in the Hearts→Clubs→Diamonds→Spades cycle after Diamonds is Spades, so the missing card's suit is Spades.

4. Continuing the column confirms it: the cell below the missing card is 5♥(Hearts), the suit that follows Spades in the cycle.

Both attributes are derived independently and agree with every other card in the grid without a single exception, so the deduction is consistent.

Therefore, the missing card is the Jack of Spades.