Tunnels cover art courtesy Scholastic, Inc. Tunnels cover art courtesy Scholastic, Inc.

Who will spellbind young moviegoers once Deathly Hallows has come and gone? Warner Bros. has picked up the big-screen rights to the seven-book Septimus Heap series, while Relativity Media has acquired Tunnels, a children's fantasy series out of the U.K.... Also per Variety, Aaron Sorkin is penning three films for DreamWorks, kicking off with The Trial of the Chicago 7, which Steven Spielberg hopes to direct.... Per the Reporter, Naomi Watts will star opposite Clive Owen in the thriller The International.... Tim Robbins and Martin Landau have joined the fantasy feature City of Ember, starring Bill Murray.