In essence, Jane, Jesse's lover from season 2 of Breaking Bad, overdoses on heroin while lying in bed with Jesse. Walt moves Jane over while breaking into her apartment to try to wake Jesse up. Jane chokes on her own vomit as a result of this. Walt offers her no assistance. This fells Jesse with guilt throughout the series thinking he's responsible, he only learns that Walter was responsible in the 3rd to last episode, Ozymandias.
