Robert Black prided himself on his encyclopaedic knowledge of the UK's road network, but it was one wrong turn that proved his undoing.
The serial killer's decision to double back on himself after snatching a little girl from the Scottish village of Stow saw him drive straight into the hands of police officers who had just been alerted to a suspected abduction.
He later described that date - Saturday July 14 1990 - as the day "the roof fell in''.
The terrified six-year-old was found in the back of his delivery van, bound, gagged, hooded and stuffed head-first into a sleeping bag.
If she had remained in that state, medical experts claimed, she could have been dead within 15 minutes.
Black had sexually assaulted her in the back of his blue Ford Transit moments earlier in a lay-by beside a disused quarry two miles north on the main A7 Galashiels Road.
But his next move - to turn round and drive back through Stow on his way south to Galashiels - sealed his fate, inadvertently saved his victim's life and finally brought his murderous reign of terror to a shuddering halt.
Black, who had approached another girl in the village an hour beforehand, only to be scared off by her dog, initially said nothing as the little girl was recovered from the van.
However, as he was driven to a police station, the calculating killer started to talk, recounting the events of the day in chillingly understated fashion.
"What a day it's been,'' he said.
"It was a rush of blood. I've always liked young girls since I was a young kid.''
Fortunately, Stow resident David Herkes had witnessed the abduction taking place and had told police immediately.
Mr Herkes had been on the other side of the road as the young girl, who was on her way home after calling at a friend's house to find no-one in, walked along the pavement past the parked Transit.
He noticed her stop at the passenger's door - then suddenly she was gone, her feet whipped from her as Black pushed her into the footwell.
Later, Black's petrified victim, who cannot be identified for legal reasons, told officers what happened.
"He wasn't looking at me then but then he looked at me,'' she said.
"I didn't know he was a bad man then.
''He said sorry but then he grabbed me round the waist and bent me over and pushed me under the chair of the van.''
Black drove off before Mr Herkes could do anything, but he had managed to note the number plate and immediately ran to the local police station.
It was 20 minutes later, as police were just beginning to mount the search, that Black drove straight into them on the Galashiels Road.