While Mike takes Jesse with him doing pickups, Walt's left in the dark and cooking alone.
Breaking Bad – Season 4, Episode 5: “Shotgun”

While Mike takes Jesse with him doing pickups, Walt's left in the dark and cooking alone.
Walt and Skyler have to come together to sell their lies to Hank, when Walt finds out his brother-in-law is helping on a new case.
Walt tries to secure safety in a post-Gale lab, whereas Jesse only falls deeper into despair.