According to Arnold written by Giles Milton performed by Nick Rawlinson and David Thorpe on Audio CD (Unabridged)

Meet Arnold Trevellyan charismatic, exuberant and somewhat strange. His love of mushrooms is matched only by a passion for Flora, his wife of twelve years. One day, while searching for mushrooms, Arnold makes a wondrous discovery that will turn his world upside down. He abandons Flora and heads to the South Pacific where he finds himself marrying the queen of the remote tropical island. But all is not as...

it seems in Arnolds idyllic realm. In a series of cassettes to his oldest friend, he reveals he is trapped in an international conspiracy in which mushrooms hold the key to life or death.