Episode 2x7, The Other 48 Days

Eko doesn't talk for 40 days after killing two of the tailies' attackers.

Episode 2x8, Collision

Against Ana-Lucia's wishes, Eko takes Sawyer, carrying him on his shoulders, to Jack.
He agrees to take Jack to Sayid, only if Jack takes no guns and no one else.

Episode 2x9, What Kate Did

Eko shows Locke that he has some of the Orientation film and they splice the two together to learn that the computer should not be used for anything other than entering the code.

Episode 2x10, The 23rd Psalm

Eko forces Charlie to show him where Charlie got the Virgin Mary statue.

Charlie takes him into the jungle, where Eko sees the black smoke , but he is not afraid of it. The smoke appears to have images in it.
Charlie shows Eko the plane, where he finds his dead brother. He asks for his brother's forgiveness and then burns the plane with his brother inside.

Episode 2x12, Fire + Water

Eko thinks that Charlie's dreams might mean that Aaron is in danger and suggests that he baptize the baby. When Claire approaches him and asks what will happen if Aaron is baptized and she is not, Eko offers to baptize her as well.

Episode 2x15, Maternity Leave

Eko figures out that Jack and Locke have a prisoner in the armory and asks to talk to him. He confesses to Henry that he killed two men on the first night on the island, and he asks Henry's forgiveness. Then he cuts the two long strands off his beard.

Episode 2x18, Dave

Eko is building something and lets Charlie help, but he won't tell Charlie what it is.

Episode 2x19, S.O.S.

Eko continues to build his church with Charlie. When Bernard asks for help building his S.O.S.

sign, Eko turns him down. Bernard asks for some of their logs and Eko says that they need them.

Episode 2x21, ?

Eko dreams that Ana-Lucia tells him to help Locke. Yemi is also in the dream, telling Eko to help Locke. Yemi says to ask Locke about the question mark.

When Eko goes to the hatch, he sees that Ana-Lucia and Libby have been shot, but he's able to persuade Locke to go with him, under the guise of searching for non-Henry Gale. Eko asks Locke about the question mark and Locke acts as if he doesn't know what Eko is talking about. Eko headbutts Locke.

When Locke comes to, he finally gives Eko the drawing of the blast door diagram. From the drawing, Eko tries to figure out where the question mark could be. As it gets dark, they walk through the jungle and come upon the burned out plane that fatally injured Boone. They make camp, and in a dream, Locke sees Yemi calling to Eko and having him climb a cliff.

The next morning Locke tells Eko of the dream and Eko climbs the cliff. From up above he can see a circle or a question mark on the ground where nothing is growing. He climbs down and bangs around the plane until he hits something metal in the ground. The two dig out two doors, and open them to climb down the hatch. It's another station.

They find an Orientation Video and find out that what they have found is Station Five, The Pearl Station, of the Dharma Initiative. It is an observation station, where team members are asked to record what participants of The Swan Station are doing. The Swan Station members do not know that it's an experiment or that they are under surveillance.

Locke thinks his whole life is meaningless, but Eko tells him of Eko's brother and how it can't be a coincidence for both of their planes to crash on this island. He tells Locke that his hatch work is more important than ever.

Episode 2x22, Three Minutes

Eko sits at the computer, happy to type in the numbers. When Charlie comes, Eko asks if Charlie would bring his things from the beach. Charlie asks about the church and Eko says he has a new job now. Charlie is upset and storms out.
Eko helps Michael clean up Libby's blood from the floor and they speak of hell.

Episode 2x23, Live Together, Die Alone

Eko and Locke argue over whether or not to punch in the code in the computer. Eko says he is going to do it, but Locke doesn't want him to. Locke and Desmond cause a lockdown with Eko outside the computer room. Eko gets Charlie's help to find dynamite and tries unsuccessfully to blow the blast doors open.