The final monster card of the eighth floor, whose spider is now permanently inside Carl's chest.
The Eye of the Bedlam Bride is the last card of the eighth floor and the one thing Tempest refuses to let her uncle skip. "You still haven't mentioned that whole thing with the homeless shelter, or that last card, the Eye of the Bedlam Bride. The spider is in him now, isn't it?"
Quasar's answer is a shrug and the only honest thing available: "nobody really knows how that's going to turn out with the spider in his chest." The card's occupant, the demigod spider Shi Maria, refused to be discarded and instead wrote herself into Carl's body, and Quasar's entire summary of the previous floor collapses into it — Carl "fucked up a little in the end and now has a spider stuck in his chest".
It is the one item on the board that neither the lawyers nor the audience can price.
A monster card whose namesake eye belongs to a spider — and which no longer exists as a card so much as a tattoo across a man's chest.
The eighth floor's final and least understood card, now fused into Carl as an unpredictable permanent condition.
Also appears in books you've already read — spoiler-safe to their endings: