Foyle's War creator Anthony Horowitz has said the current series of the detective drama will probably be his last.
The ITV drama starring Michael Kitchen - now set in the Cold War - returned to television this month after a long absence.
But writer Horowitz told the Radio Times: "Nothing is ever certain - and Foyle's War can always return without me - but I think this series will be my last.
"I've written 22 episodes. That's an awful lot of crimes, clues, bodies, suspects, mysteries and chases," he said of the drama, which began in 2002.
"Although I've had great support from the Imperial War Museum, I've still read four or five books for every episode and frankly there's no more room on my shelves."
Horowitz said he thought the current eighth series was his "best work" but he added: "It might be best to quit while we're ahead. We'll see."
Foyle's War began in 2002, originally set in the Second World War.
ITV cancelled the series in 2007 but after thousands of viewers complained the drama returned.