Bill had been at home, sitting out in the park and drawing Myrkvan as she investigated all manner of interesting things, when he'd felt it. Suddenly, there was one more of them. More Losers. He reached out like Abra had taught him years ago, although he was nowhere near as strong as her or Dan, and grinned as he realized that it was Ben. He felt young, though. Like the age he himself should have been.
He checked in with Richie and Eddie, and it was decided that they were going to go get their friend. First, Bill had to pick up all his art stuff before Myrkvan decided to investigate pencils and charcoal - he did not want to have to explain or deal with that particular stomach-ache or its aftereffects to anyone - and then he left a note for whoever else was at home, explaining what had happened. They could sort out Ben's room once they'd collected him and brought him back to meet everyone.
Lifting a sling ring, Bill quickly met up with his friends, and then they went to get Ben and bring him home.