What happens when the truth about Arthur Matthews comes out? Arthur Matthews was well known to the Smith family but what happens when one day he goes missing?

Ben Barnes
As
Arthur Matthews/Henry Jones

Nick Jones
As
Julian Smith

Margot Robbie
As
Allie Grimes

Tom Holland
As
Logan Smith

Lilly Collins
As
Isabella Smith

Timothee Chalament
As
Nolan Walker

Tanner Bunchana
As
Oscar Walker

Dylan Minnette
As
Charlie Dixon

Mckenna Grace
As
Lucy Walker

Ian Armatige
As
Thomas Williams

Ellie Fanning
As
Charlotte Williams

Robert Downey Jr
As
Tobi Walker