The search for the next card key holder brings Michael and Lincoln to the Treasury Department. Sucre and Bellick track T-Bag, who arouses suspicions and forms an uneasy alliance at his new job. Wyatt uses his personal touch with Gretchen.

Lincoln takes members of the team to Las Vegas where Sucre gets an indecent proposal. Sara learns about Michael's condition, and Roland pushes his luck too far. Gretchen teams up with T-Bag who makes an offer to Michael he cannot refuse. Meanwhile, the secrets in Whistler's bird book are finally revealed.