Here are the secrets and deaths:
Dr. Edward Armstrong operated and accidentally killed his patient, Louisa Clees, while drunk. Died from being pushed off a cliff.
Emily Brent dismissed her maid Beatrice Taylor after she became pregnant, and the maid committed suicide by drowning herself. Died from being injected with cyanide.
William Blore committed perjury during the trial of an accused bank robber Stephen Landor, who died in the prison. Died from a blow to the head.
Vera Claythorne allowed Cyril Hamilton, a small boy in her care, to swim out to sea and drown. Cyril was first in line to inherit a vast legacy; the second was Vera's lover. Was the last person alive. Commited suicide (hung herself).
Phillip Lombard abandoned a party of twenty-one native retainers to die in the African bush. Was shot by Vera (they were the last 2 on the island, and he lunged at her before he shot her).
General John Macarthur deliberately sent his wife's lover and his subordinate, Arthur Richmond, on a suicidal mission during World War I. Died from a blow to the head.
Anthony Marston accidentally ran over and killed two children, John and Lucy Combes, while driving recklessly. Died of poison.
Mr. and Mrs. Rogers let their invalid employer Jennifer Brady die by withholding her medication in order to claim a large inheritance. Mrs. was poisoned and Mr. was hit with an axe.
Justice Lawrence Wargrave gave the death penalty to accused murderer Edward Seton despite evidence supporting his innocence. Suicide, but it looked like he was murdered.