Paul Selby nears the end of an amazing challenge
On Sunday morning, five British athletes reach the end of an epic journey, the Flora 1,000 Mile Challenge.
Set the task of running 1,000 miles in 1,000 consecutive hours - at the rate of a mile per hour - up and down the course of the London Marathon, the plucky runners are now on the home straight.
They are scheduled to complete the final mile at 0800 BST on Marathon race day in Greenwich.
But the pain does not stop there - the remaining challengers will then attempt to run the 26.2 mile course of the London Marathon to decide the winner.
Certainly, it promises to be a thrilling climax to one of the most unique events in running history.
The idea for the epic endurance event came 194 years ago when noted sportsman and infamous gambler Captain Robert Barclay undertook the feat for a wager of 16,000 guineas.
Aided by supporters who slapped him round the face to keep him awake, and a pair of pistols to combat the gangs who attempted to nobble him, Barclay somehow managed to pull it off.
Now, nearly two centuries later, three men and two women - Rory Coleman, David Lake, Paul Selby, Sharon Gayter and Shona Crombie-Hicks - are about to repeat history.
THE ORIGINAL NUTTER
Name: Captain Robert Barclay Allardice
Attempted: 1,000 miles in 1,000 hours
At: Newmarket Heath
Won: 16,000 guineas
Six athletes originally began the challenge on 2 March, but Lloyd Scott, who ran last year's marathon in a diving suit, withdrew after 335 miles due to personal reasons.
By next Sunday, the remaining five contenders will have spent 42 consecutive days together and have run the London Marathon course more than 38 times.
But covering a mile an hour, every hour, every day and night for six gruelling weeks has taken its toll.
The competitors have endured all manner of aches, pains and blisters, as well as chronic lack of sleep.
Living together on a special custom-designed coach 24/7, the opportunity to rest has been limited as the athletes complete the miles two at a time: one at the end of the hour and the second within the following 60 minutes.
But, with the end now in sight, they will be more determined than ever to see the challenge through.
The final mile will be shown live on BBC1 at 0800 BST on Sunday 14 April.