The battle for yellow jersey supremacy could finally begin on the first of two days in the Pyrenees starting Saturday, although favourite Chris Froome is giving nothing away.
Stage eight is a 195 km trek from Castres to the summit of Ax-Trois-Domaines.
There are only two climbs, but the formidable Col du Pailheres is an 'hors categorie' (unclassified) monster at 15.3km long with an average gradient of eight percent, and some passages at 10.5.
It will feature for the fifth time on the race since 2003, an indication of its attraction to race organisers keen to provide drama in one of the world's most spectacular mountain ranges.
From the highest point of this year's race (2001 metres altitude), a long descent towards Ax-les-Thermes ensues before the bunch tackles the 7.8km (average gradient of 8.2) climb to the summit finish.
Fans hoping for fireworks between Froome, last year's runner-up and two-time champion Alberto Contador, may be forced to wait, however, especially with many climbs to come in the final week.
Nairobi-born Briton Froome played down suggestions stage eight is where he and Spanish rival Alberto Contador, a two-time race winner, will first cross swords.
"I can't say now what's going to happen tomorrow. We have to see how the race pans out. We'll let the legs do the talking," Froome told French television.
Sunday's ninth stage features a total of five categorised climbs but has no summit finish, instead culminating in the Pyrenean town of Bagneres-de-Bigorre.