Walkin' on the Sun
performed by Smash Mouth

Danny asks Doug for a letter of recommendation at IPS because he wants a promotion to become a driver, just like Doug. Doug doesn't want his annoying cousin to work with him, so he tries to get out of writing the letter. Carrie thinks Doug is being ridiculous, so she decides to write the letter herself. Danny ends up getting the job, and puts Doug's driving skills to the test when he manages to do Doug's delivery route faster than Doug has ever been able to finish it.

When new evidence is uncovered that relates to a shooting death near Atlantic City in 1997, the team reopens the murder of a hitchhiker on his way back to Philadelphia.