Danny Boyle’s wickedly witty thriller Shallow Grave (B+) features Kerry Fox, Christopher Eccleston and Ewan McGregor as insular flatmates in search of a fourth, who turns out to have mysterious money and crime connections. Boyle is observant and twisty as his trio of antiheroes confronts some shades of gray that are murkier than ever surrounding their new domicile denizen. It’s entertaining and suspenseful.