S04E01 - Highest Castle, Deepest Grave -- Young girl kills her mother and mother's lover, resulting in mental instability
S04E02 - No Bottles ... No Cans ... No People -- Gangster has people knocked off and dumped in an incinerator
S04E03 - Wednesday, Ladies Free -- customer of prostitute is upset when she leaves the business, he starts murdering other women
S04E04 - 3,000 Crooked Miles to Honolulu -- armored car employees are murdered with a bazooka
S04E05 - Two Doves and Mr. Heron -- drugs, hints of homosexuality, hippies, a betrayed lover
S04E06 - ... And I Want Some Candy and a Gun That Shoots -- mass murder by sniper
S04E07 - Air Cargo -- Dial For Murder -- guy is murdered because he knows too much about a racket involving fraud
S04E08 - For A Million ... Why Not? -- armored car employees are killed in a nasty way
S04E09 - The Burning Ice -- a doctor hires someone with a terminal disease to murder his wife
S04E10 - Rest in Peace, Somebody -- a former cop who was dealt with harshly by McGarrett is out for revenge
S04E11 - A Matter of Mutual Concern -- racism and murder
S04E12 - Nine, Ten -- You're Dead -- a guy is shot dead while driving down the street
S04E13 - Is This Any Way to Run a Paradise? -- a "capitalist pig" is strangled in his bed
S04E14 - Odd Man In -- no one dies, but involves some nasty people
S04E15 - Bait Once, Bait Twice -- young girl kidnapped, man tricked into coming out of protective custody so he can be assassinated
S04E16 & S04E17 - The Ninety-Second War, Part I and II - nuclear annihilation, young girl is tortured so father will do Wo Fat's bidding
S04E18 - Skinhead -- racism and rape
S04E19 - While You're At It, Bring in the Moon -- big business hijinks, murder
S04E20 - Cloth of Gold -- 3 guys are poisoned by father of girl who they forced to act in porno movies
S04E21 - Good Night, Baby -- Time to Die! -- dunno about this one yet
S04E22 - Didn't We Meet at a Murder? -- 3 people with a shady past are blackmailed into shooting a gangster
S04E23 - Follow the White Brick Road -- drug addiction in the military
S04E24 - R&R&R -- psycho "loser" kills wives of his former platoon comrades in Vietnam