Simon Feil

When a well-respected mathematician is found dead, Holmes and Watson set out to solve a murder and the purpose of the highly guarded equation he was trying to decipher. Meanwhile, Watson is conflicted when the son of a former patient approaches her for a loan. Jeremy Jordan guest stars as Joey Castro, the son of Watson's former patient.

Following Frank's dinner with mob lawyer Angelo Gallo, Gallo is shot, and Frank narrowly escapes with his own life. Meanwhile, Danny is called for jury duty, and winds up being the sole dissenting opinion in a murder trial. Chazz Palminteri guest stars.

Instructed by Stone not to talk to anyone, Naz breaks his promise when his parents arrive at the precinct. Later, he's transferred to Central Booking and, after pleading not guilty at his arraignment, to Rikers Island. Detective Box talks to Don Taylor, Andrea Cornish's stepfather, about the victim's troubled past. At his apartment, Stone bonds with his son Gooden before Kara, Stone's ex and Gooden's mom, drops by to pick up the boy. Helen Weiss, a prosecuting attorney, meets with Box to discuss the evidence against Naz.

While Elizabeth is away on a retreat thinking about her presidential campaign, her staff tries to secure an international agreement to protect citizens who have been displaced due to global warming. Also, the staff works to contain a measles outbreak that threatens the life of Daisy's daughter, Joanna.