On his first full day with the Knights, Roy arrives at the clubhouse, only to become the victim of a number of practical jokes, most played by Bump. Bump nearly saws up Roy's bat, Wonderboy, but Roy successfully saves it. Bump implies that he purposely tricked Memo into sleeping with Roy, even though Memo is Bump's own girlfriend. Roy tries to forget about it and goes to batting practice, where he blasts every ball the star pitcher gives him.
Pop is ecstatic to have found such a good hitter, but he orders Wonderboy to be weighed and checked to make sure it is a legal bat. Inspired by Roy, most of the players begin to play better, while Bump plays better because he feels threatened by Roy's presence. Shortly before game time, Pop brings in a hypnotist who is supposed to help the players feel better and improve their performance. Roy has a strange vision in which he is lost underwater, searching for a mermaid who spurns him. He rips himself awake and refuses to undergo any more hypnosis, causing an angry Pop to bench him until he agrees to the hypnotism.
The team begins to lapse back into mediocrity, each of the players following his own sort of superstition. Many of the players have fans who laud them; the most famous is Otto P. Zipp, a dwarf who roots for Bump and Bump alone. Roy, as he waits for Pop to break down and allow him to bat, dreams of Memo, who now hates him for what happened between them.
Finally, one game, Bump misses an important catch, and Pop orders Roy to bat for Bump, telling him to "knock the cover off it." Roy does just that, on the first pitch, smashing the cover off while the inside of the ball soars into the outfield. At the moment that he hits, a crack of thunder is heard, and within seconds there is a sudden rainfall that does stop for three days. The game is called off due to the rain, to be replayed later in the season. The drought is over, and soon the field becomes bright and green.
Bump, starting to feel the threat of Roy more intensely, starts hustling on the field. One day, however, Bump hustles a bit too hard and smashes himself up against the wall while trying to catch a ball, injuring himself seriously. Roy replaces Bump in the lineup, but there is more curiosity about how Roy manages to knock the cover off the ball.
Roy continues to bat well and field well, inspiring the Knights, who quickly start to win games. Pop is worried, however, as he notes that Roy tends to go for "bad balls"; Pop mistrusts a bad-ball hitter because they "sometimes make harmful mistakes." Roy, though, continues to break records, smashing hits and catching anything he sees—including a small bird that happens to fly over the outfield. The bird dies when Roy, thinking it a ball, snatches it out of the sky in his glove.