Agatha saw George running into the church and ran after him, with Toni pounding after her. George was disappearing through a door at the back of the church where stairs led to the tower. Agatha ran up the stairs, panting and gasping as she neared the top. She staggered out onto the roof.

Mrs. Andrews was standing up on the parapet. “I can fly,” she said dreamily. “Just like Superman.”

George made a lunge for her-but too late.

With an odd little laugh, Mrs. Andrew sailed straight off into space. George, Agatha and Toni craned their heads over the parapet. Mrs. Andrew lay smashed on a table tombstone, a pool of dark blood spreading from her head.

George was white-faced. “What on earth came over her? She was a perfectly sane woman.”

“The jam,” said Toni suddenly. “I think someone’s put something in the jam.”

“Get down there,” said Agatha, “and tell the security guards to seal off that damned tent.”

She was about to run after Toni when George caught her arm. “What’s this about the jam?”

“Toni noticed that an awful lot of teenagers were queuing up outside the jam tent and coming out looking stoned. I’ve got to get down there.”

When they arrived outside the church, a woman came up to them looking distraught. “Get an ambulance. Old Mrs. Jessop’s jumped into the river.”

Police were beginning to shout through loudhailers that everyone was to stay exactly where they were until interviewed.

“Thousands of them,” gasped Toni. “I told Bill there was something wrong with the jam.”

Chapter Two

SIR CHARLES FRAITH, a friend of Agatha’s, placed his slippered feet on a footstool in his drawing room and switched on the television to BBC news.