When Mark is shot, everybody assumes that the hitman was aiming for Ironside. It soon transpires, however, that Mark was the intended victim. With no apparent motive, and no clues as to who hired the assassin, can the team find the people responsible before they find out that Mark is still alive?

A military-issue fragmentation grenade is used in an attack on two Vietnam veterans, one of whom - a friend of Mark's - is killed. When it transpires that another of the pair's old unit has come under similar attack, the Chief sets out to trap the killer, using Ed in a cunning disguise as bait.

Mark's graduation from law school coincides with the arrest of a caretaker that he has befriended. Believing the man innocent, he finds the weight of the law stacked against him, and quickly becomes disillusioned with his new career. Should he turn his back on law altogether, though, or should he just find another way to devote himself to justice?

A friend of Mark's is being unfairly shaken down by a crooked loan shark with crippling interest demands. Worried for his friend Mark goes undercover, despite objections from the Chief, and sets himself up as a potential customer in the hope of digging the head of the operation out of the woodwork.