Tonight in HD: July 26

Grey's Anatomy (TV2, 8.30)

Friends (TV2, 6.30, R)

Ross initiates a threesome with his wife and her female friend – and gets left out. Part two of two.

Shortland Street (TV2, 7.00)

Callum and Rachel go head to head; Tracey fights for Kitu; TK and Roimata get away from it all.

Missing Pieces (TV3, 8.00, R)

Stacey Mullen was the result of a one-night stand between old school friends. Her father Dale disappeared to Australia. Now, after 17 years without contact, she wants to meet him.

Grey’s Anatomy (TV2, 8.30)

News of the incoming mass causalities after a gunman opens fire at a local college hits the staff hard when they must spring into action, even while their own wounds are still fresh. Reviews: Unreality Shout, Daemon’s TV.

NCIS (TV3, 8.30, 5.1)

A naval officer and the shock jock who is interviewing him are both shot to death during a live show. Reviews: The TV Obsessed, Boom Tron.

Private Practice (TV2, 9.30)

Addison seeks Dr Rodriguez’s help to save the life of her mother’s partner. Reviews: Reviewer, Examiner.

Medium (TV3, 11.10, 5.1, R)

Allison mysteriously awakens under a freeway underpass to discover she has no recollection of the previous six hours of her life.