The Harry Potter series asks us to accept moving staircases, soul-splitting murder and a sport that can last three months. Fair enough—magic comes with the territory. Harder to swallow are the moments when the franchise forgets its own rules, hands its characters an obvious solution or introduces a spell powerful enough to unravel the next five books. Peter Pettigrew’s suspiciously unnoticed sleepovers are only the beginning of these Harry Potter plot holes.
