Six leg-busting climbs will tear the Tour de Yorkshire to pieces on Sunday.
The overall winner of the four-day UCI 2.1 stage race will be crowned in Leeds after 189.5km of combat.
And whoever tops the podium will have earned it, with six categorised climbs featuring on a daunting route out of Halifax (12.10pm).
After Max Stedman‘s heartbreaking mechanical on stage three, James Lowsley-Williams leads Canyon Eisberg‘s general classification challenge.
He is 1min 23sec down on race leader Magnus Cort Nielsen, of Astana. Reigning champion Serge Pauwels, from Dimension Data, is poised in fourth at 16sec.
Here we take a closer look at the six climbs which will decide the overall winner of the 2018 Tour de Yorkshire…
HEBDEN BRIDGE
The first climb of the day comes after just 16km and covers 7km at an average gradient of 4.6 per cent.
The Cote de Hebden Bridge won’t be decisive but will certainly soften up the peloton and thin out the weaker of the climbers.
Greg van Avermaet, who is second on general classification at 10sec, tackled the climb in the inaugural Tour de Yorkshire in 2015.
The Belgian star averaged 26.6kmph and 408watts as he crested the climb inside 16 minutes that day.
GOOSE EYE
Short and sharp, the Cote de Goose Eye arrives at 31km. At an average gradient of 10 per cent, it is a five-minute test of strength.
Etienne van Empel, the mountains jersey winner last season and 14th at 29sec this time around, averaged 18kmph and 384w in 2015.
BARDEN MOOR
The Cote de Barden Moor is the shortest of the day’s climbs at just 1km. Coming after 48.5km, it’s 9.5 per cent average gradient will be a real test.
PARK RASH
Stedman did a reccy of this stage last month and powered to the Strava KOM on the Cote de Park Rash, which will be crested at 77km.
Weighing in at 54kg, the 22-year-old climber averaged 358w and 17kmph as he completed the 2.2km ascent in little more than seven minutes.
In terms of average gradient, Park Rash is the day’s stiffest test at 10.5 per cent.
GREENHOW HILL
There is a gap of 61km between the summits of Park Rash and the Cote de Greenhow Hill, which looms large at 134.7km.
At 3.3km, it is the second longest climb of the day and boasts an average gradient of 8.2 per cent.
Johnny McEvoy, who was in the break on stage three, completed this ascent in little more than 11 minutes during his reccy last month.
OTLEY CHEVIN
The Cote de Otley Chevin is the final categorised climb of the day. It is crested 25km from the finish line in Leeds.
The climb covers a distance of 1.4km at an average gradient of 10.3 per cent and could offer a springboard for a race-defining move.
Pauwels’ Dimension Data team-mate Scott Thwaites, who hails from Steeton in West Yorkshire, raced up this climb inside five minutes at an average power of 495w in 2016.
ANY MORE?
There may not be anymore classified climbs but there is barely any flat in the whole 189.5km of Sunday’s stage.
Even the final 10km features three or four kickers, any one of which could provide a platform for a stage or race-winning move.
MAKING A POINT
There are two intermediate sprints as the points classification reaches a climax on stage four of the Tour de Yorkshire.
Harry Tanfield currently sits in second position, six points adrift of race leader Magnus Cort Nielsen.
The 23-year-old, from Great Ayton, will wear the green jersey with his Astana rival pulling on the blue jersey once again.
However, neither man is likely to reach the final sprint, at Arthington, which arrives just 16.5km from the finish.
The first sprint comes in Kilnsey at 67.5km. With three categorised climbs already in the bank, it will take a huge effort for the pair to contest this one, too.