Which playing card replaces the question mark?

Grid-based playing-card puzzles are read along a boustrophedon (snake) path across the rows, and each card in that reading order is linked to the next by two independent rules applied together: a fixed rank progression under modulo-13 arithmetic (Ace = 1 through King = 13) and a suit that cycles through a fixed repeating order.

1. Reading the grid as a snake path: Row 1 left-to-right, Row 2 right-to-left, Row 3 left-to-right, produces one continuous 18-card sequence.

2. Testing the rank rule on known cards confirms it: 7 of Hearts leads to Queen of Clubs (7 + 5 = 12), Queen of Clubs leads to 4 of Diamonds (12 + 5 = 17, which wraps to 4), and so on throughout the sequence — each rank is the previous rank plus 5, wrapping modulo 13.

3. Testing the suit rule confirms a fixed 4-step cycle: Hearts to Clubs to Diamonds to Spades to Hearts, repeating every four cards in the sequence.

4. The card immediately before the missing card is the 8 of Hearts. Applying the rank rule: 8 + 5 = 13, which is King. Applying the suit rule: the suit after Hearts in the cycle is Clubs. So the missing card is the King of Clubs.

Cross-check: this can be verified moving forward too — from a King (13), the next rank is 13 + 5 = 18, which wraps to 5, and the next suit after Clubs is Diamonds, predicting a 5 of Diamonds immediately after the missing card, which is exactly the card shown there. Both rules hold consistently across all 18 cards in the sequence, confirming the King of Clubs.