Characters

The story starts out with the eight guests receiving invitations to "Indian Island" from U.N.Owen. When the guests arrive they are greeted by the two staff Mr. and Mrs. Rogers. And no host.

After the guests have finished dinner, on the first night, a record is played accusing each of them of a crime. As they are trying to figure out who their mysterious host is, the first murder occurs.

***

Anthony Marston

Anthony Marston arrives on Indian island expecting a visit with friends. Little does he know he will be the first to go.
As the guests are discussing the horrid accusations of the record, Marston chokes on poisoned whiskey and dies.

“Ten little Indian boys went out to dine;
One choked his little self and then there were nine.”

***

Mrs. Rogers 

When the record is played Mrs. Rogers drops the tray she is carrying and is very frightened. The next morning the guests find that Mrs. Rogers apparently died in her sleep.
The guests hope to leave that morning, but the boat that regularly delivers supplies to the island does not show up.

“Nine little Indian boys sat up very late;
One overslept himself and then there were eight.”

***

General Macarthur

Blore, Lombard, and Armstrong decide that the deaths must have been murders and determine to scour the island in search of the mysterious Mr. Owen. They find no one, however.
Meanwhile, the oldest guest, General Macarthur, feels sure he is going to die and goes to look out at the ocean. Before lunch, Dr. Armstrong finds the general dead of a blow to the head.

“Eight little Indian boys traveling in Devon;
One said he’d stay there and then there were seven.”

***

Mr. Rogers

 The next morning, the guests find that Rogers has been killed while chopping wood in preparation for breakfast.
At this point, the guests feel sure the murders are being carried out according to the dictates of the nursery rhyme. They also realize that the dining-room table initially featured ten Indian figures, but with each death one of the figures disappears.

“Seven little Indian boys chopping up sticks;
One chopped himself in halves and then there were six.”

***

Emily Brent

After breakfast, Emily Brent feels slightly giddy, and she remains alone at the table for a while. She is soon found dead, her neck having been injected with poison.
At this point, Wargrave initiates an organized search of everyone’s belongings, and anything that could be used as a weapon is locked away. The remaining guests sit together, passing time and casting suspicious looks at each other.

“Six little Indian boys playing with a hive;
a bumblebee stung one and then there were five.”

***

Sir Justice Wargrave

Finally, Vera goes to take a bath, but she is startled by a piece of seaweed hanging from her ceiling and cries out. Blore, Lombard, and Armstrong run to help her, only to return downstairs to find Wargrave wearing a judges wig, draped in a curtain that resembles courtroom robes and bearing a red mark on his forehead. Armstrong examines the body and reports that Wargrave has been shot in the head.

“Five little Indian boys going in for law;
one got in Chancery and then there were four.”

***

Dr. Armstrong

That night, Blore hears footsteps in the hall; when he checks, he finds that Armstrong is not in his room. Blore and Lombard search for Armstrong, but they cannot find him anywhere in the house or on the island. When they return from searching, they discover another Indian figure missing from the table.

“Four little Indian boys going out to sea;
a red herring swallowed one and then there were three.”

***

Mr. Blore

Blore is hungry and tired of waiting in the hot sun away from the house. Vera doesn't want to go back to the house so Lombard stays with her. After a while of waiting for him to return Vera and Lombard go after Blore and find him on the terrace, skull crushed by a bear-shaped clock.

"Three little Indian boys walking in the Zoo;
A bear hugged one and then there were two."

***

Philip Lombard

Vera and Lombard retreat to the shore, where they find Armstrong’s drowned body on the beach. Convinced that Lombard is the killer, Vera steals Lombard’s gun and shoots him.

“two little Indian boys sitting in the sun;
One got frizzled up and then there was one.”

***

Vera Claythorn

Vera returns to her bedroom to rest, happy to have survived. But upon finding a noose waiting for her in her room, she feels a strange compulsion to enact the last line of the nursery rhyme, and hangs herself.

“One little Indian boy left all alone;
he went and hanged himself and then there were none.”

Here is a summary and other information on Wikipedia(warning the section labeled "Post Script" contains spoilers):

http://en.wikipedia.org/wiki/And_then_there_were_none