The huge albino's name is Silas, and he wears a spiked cilice belt around his thigh, which is causing him to limp.
He's retreated to a luxurious brownstone and his spartan bedroom to make a phone call to report to his Teacher all that he's done (i.e.: killed the three sénéchaux and the Grand Master Saunière).
Silas informs the Teacher that all four of the men told him that the legendary keystone (an engraved tablet that reveals the final resting place of the brotherhood's greatest secret) resides in Paris, at the ancient church Eglise de Saint-Sulpice.
The Teacher commends Silas for his good work, and then commands him to get the keystone immediately.
But first Silas's allowed the time to purge his soul of his sins by stripping down naked, tightening his cilice, and then whipping a heavy knotted rope over his shoulder until his back bleeds, as penance.
(Father Josemaría Escriva, the Teacher of all Teachers, created the sacred mantra of "pain is good" to go along with this practice of corporal mortification. Pleasant, isn't it?)