I might miss a few points so if I miss anything hopefully someone else will catch it and fill in the gaps. The episode opened with Hiro and Ando at a small diner in Midland, Texas. A really cute redhead there has the ability to remember pretty much everything she sees and hears. For example she has a book of Japanese that she looked over for a week and is rapidly learning the language. Anyways, she goes into a store room and is killed by Sylar. So Hiro goes back in time to the previous day to prevent her from coming in to work the next day. He told Ando he would be back in five seconds, but wasn't, however his picture is on a corkboard standing next to the waitress celebrating her birthday.
Isaac Mendez was captured by Mohinder's gf and glasses guy. He's being held at a paper factory where Glasses Guy works. He overcame the heroin addiction and they wanted to help him learn to use his power w/o the drugs, but glasses guy needs him to paint more pictures so he can save Claire. So in the end he tells M.'s gf to talk him into taking the heroin and painting the picture. There was a hint that maybe she has some sort of presuasive ability and a reference to her past like, "have you forgotten what you were when I found you?" Something like that.
Mohinder scattered his father's ashes and went back to work at the college. He met up with an old flame who tried to convince him to come work for a genetics company (I think) but he had to give up his father's theories. M. also discovered that he had a sister who died when she was little, and he's had two dreams where this adolescent w/ longish hair and a soccer ball appeared in them. The first dream was him and his father arguing about his father going to USA, and then his mother telling his father to go. In the second dream he witnessed his father's murder. When M. woke up from the second dream he found a file f his father's with a picture of the boy in it and I think there was some sort of dream study with it.