Blore agrees to search the island but he thinks that maybe one of the guests is actually the murderer. Either way they decide to search the island and Blore asks if anyone has a revolver. Lombard says he does— he explains that he has gotten in “some tight places” before and always carries a revolver.
Now that the idea is out that one of the guests could be the murderer, the characters do not know whether they can trust each other. But in order to try anything to save themselves they have to put aside their suspicions, at least for a little while.
Searching the small island ends up being quite simple. Towards the end of their search they run into General Macarthur looking at the sea. He pays no attention to them and looks rather dazed. Macarthur keeps repeating “there is so little time” and that no one should disturb him. As they leave Blore says Macarthur looks insane.
Macarthur decides to do nothing because he has given up on life. For those who are still trying to live this looks like insanity, but for him he would rather die than continue to live with his guilt.
When the three men get to the top of the island Blore suggests that they light a bonfire but the others think that the murderer might have already prepared for this and told everyone on the mainland to ignore the shenanigans on the island.
They are starting to understand how comprehensive the murder's plan is.
They look down the cliff and wonder if anyone could be there. Lombard suggests he should climb down and see if there are any hidden recesses in the cliff. Blore goes to look for a rope.
The younger men in the group try to combat their lack of power through action.
Miss Brent sits on the porch knitting and Vera avoids her. Wargrave also sits on the porch and when Vera looks at him she images that she sees him pronouncing a death sentence upon Edward Seton. Vera goes down to the sea where she meets Macarthur. Macarthur tells her that he is waiting for the end, and that none of them are going to leave the island.
Vera witnesses that the older crowd does not feel the need to fight the uncertainty. They either resign themselves to it (Macarthur) or seem to feel no fear because of their sense of self-righteousness (Wargrave and Miss Brent).
Macarthur says that he loved his wife Leslie very much and then admits that this is why he sent Richmond to his death. Macarthur says that now he is alone and he will be happy to end it all. He says that one day she will also be happy when the end comes.
Macarthur admits his guilt to Vera as a last confession. He is ready to die not only because he is alone but also because he has released the secret, and hence the guilt he has been holding for so long.
Blore comes back with a rope and Lombard has gone to test some theory. Armstrong tells Blore that he is worried that Macarthur has gone crazy. Blore agrees, but says that doesn't mean that Macarthur is the murderer. Lombard returns and is soon scaling the cliff. He is a talented climber and Blore thinks this makes him even more suspicious. Lombard comes back and says he has seen nothing. The criminal must be in the house or nowhere.
After their whole search the men come up with nothing – except suspecting each other more. There is no place for the murderer to be on the island except for in the house, meaning that one of the characters is almost certainly the murderer.
They search the house easily, as it's a very modern home without hidden areas. As they are finishing their search Rogers comes out with a tray of cocktails. As the three men are up in the last corner of the house they hear a soft sound from above in the Rogers' room. They think this would be a great hiding space – in the very room where a dead body lies. But when they get up there they see that it is just Rogers who has decided to move to a different room. Blore comments that Rogers moves very quietly; none of them heard him come upstairs.
Rogers maintains the civilized façade of the gathering in an almost absurd manner. Social structures and rules are helping to maintain a thin veil of order. The house is similarly deceptive in its appearance. The modern design seems to contradict the fact that there could be a murderer hiding in their midst.
The search ends and Blore, Lombard and Armstrong are all very dirty and dusty. There is no one on the island but the eight guests in the house.
The murderer must be one of the guests, breaking down any bond of trust that might form between the characters.