Marius from Tom Hooper's "Les Misérables" will be topping the billing for "Theory of Everything," a biopic about the younger years of genius physicist Stephen Hawking, reveals Deadline.com.

The 31-year-old English actor will take the place of his compatriot Benedict Cumberbatch (in BBC TV film "Hawking") portraying the physicist who wrote "A Brief History of Time: From the Big Bank to Black Holes," now 71 years old and severely handicapped by a debilitating disease he's been grappling with for decades.

Working Title, which made "Les Mis," too, will be producing and James Marsh directing the biopic. Marsh, the director of the award-winning documentary "Man on Wire" (2008) and the drama "Shadow Dancer" (2012), will be zooming in on Hawking's younger years, particularly his studies at Cambridge in the 1960s, marked by meeting his first wife, Jane Wilde, and the onset of the first symptoms of ALS (aka Lou Gehrig's Disease).

"Theory of Everything" will start shooting in the fall.