Reagan family tensions run high when Frank and his grandson, Joe Hill, contend with a grievous insult to the memory of Joe's father, Joe Reagan. Also, Erin and Henry work together to bust an over-the-phone scammer targeting the elderly; Danny intervenes in an undercover assignment led by his spiraling former partner; and Eddie's captain takes suspicious interest in her efforts to locate a stolen puppy.

Danny and Baez's investigation into the death of a chess hustler is complicated by interference from the victim's son; Jamie tries to make amends with a man he regrets putting away as a young officer.