On Neal’s (Matt Bomer) first day back Peter (Tim DeKay) reports to the evidence warehouse for his new assignment. Feeling guilty for Peter being sidelined, Neal looks into a series of high profile unsolved robberies five years apart by the same thief (Michael Weston) who is planning his latest robbery for this week. Despite advice of Hughes (James Rebhorn) to keep his head down under the humorless watch of his new supervisor (Brett Cullen) and ride out the storm, Peter agrees to help Neal with a case that’s been nagging him for a decade.
Peter dusts off an old alias to make contact with the suspect allowing Neal time to discover that a diamond vault is the target of his next heist. Working together Neal, Peter, Diana (Marsha Thomason) and Jones (Sharif Atkins) are able to narrow the potential targets down to one, but they are 20 minutes too late to catch him in the act.
When Mozzie (Willie Garson) returns Neal comes up with a last-minute plan to catch the thief and get Peter his job back by turning the thief and fence (Laurie Williams) against each other. The team is able to get the collar, in no small part to Peter – who doesn’t stick around for the credit (but is thankful for the help of a certain bald guardian angel that helps him out at the evidence warehouse).
“Diminshing Returns” proves to be anything but as the show continues its string of strong fourth season episodes. The episode’s highlight is Neal explaining to Peter how to help with the con involving three real diamonds and a collection of fakes, and Peter being Peter and refusing the easy way out. We also get Peter and Neal finally sitting down to discuss Neal’s past as well as Neal asking Ellen (Judith Ivey) for the full truth about his father.