Cooper, Danny and Mike are suspicious of a guy named Pete Skinner who is betting on horses and has a seemingly perfect winning streak. Sam's "whale" brings his grandmother "Robby" with him to the casino and asks her to entertain her by playing bingo, but things turn out to be ugly when they make a side bet. Meanwhile, Mike convinces Danny to make a dry run to the hospital using Polly as the stand in for Delinda.