S3E10 · Fly

Complete story — includes the ending

Walt is suffering from insomnia, worried about the direction his life has taken. Unaware that Jesse has been skimming, he is also concerned that their yield is a half-pound short of his calculations. His paranoia comes to a head when he spots a small housefly in the lab, and, worried about contamination, goes to extreme lengths to kill it. Jesse, at first dismissive, begins to help as well, and when he finds out Walt has not slept in two days, slips sleeping pills into Walt's coffee. Walt tries to pinpoint the exact moment when things got out of control, and it becomes clear that the paranoia over contamination is not about the fly at all. Near delirium, Walt repeatedly refers to Jane and the night she died but stops short of telling Jesse what really happened. While Walt sleeps, Jesse cooks the batch on his own. In the parking lot the following morning, Walt refers to the missing half-pound of meth and warns Jesse that there may be hidden cameras in the lab and that he will not be able to protect Jesse if Gus finds out about the reason for the shortage.