Sam Neill, Michael Sheen, Lena Headey and Ioan Gruffud are in negotiations to topline “Mariah Mundi & the Midas Box.”

Mundi is produced by Karl Richard and Peter Bevan. Jonathan Newman (“FOSTER”) will direct from a screenplay by Gavin Scott (“Small Soldiers”) and “Gnomeo & Juliet’s” Rob Sprackling and John Smith.

The Victorian London teen fantasy thriller is based on the first of a trilogy of novels by G.P. Taylor. London’s Entertainment Motion Pictures, Barcelona’s Arcadia Motion Pictures and Belgium’s uMedia will produce.  Entertainment Motion has optioned G.P. Taylor’s whole trilogy.

Mariah Mundi’s world is torn apart by the disappearance of his parents, then the kidnapping of younger brother by unknown assailants. Aided by a Indiana Jones-ish adventurer, Captain Charity (Sheen), he sets off in pursuit, arriving at the Prince Regent, a hotel hiding a fantastical underworld.

Neill limns an arch villain, Headey his witch-seductress ally.

“Mariah Mundi” is budgeted at around $25 million, at the higher end for a European pic, but allowing it to go into production without a commitment from a U.S distributor, said Entertainment Motion’s Karl Richards, who produces with Arcadia’s Ibon Cormenzana. “Mariah Mundi” will begin lensing April 30 at the Bottle Yard studios in Bristol and on location in Bristol and Bath, Richards added.