The Double is a 1963 second feature British film directed by Lionel Harris and starring Jeannette Sterke, Alan MacNaughtan and Robert Brown.
Jane is captured by the imposter, and she is tied up (hand and foot) and gagged and left in a storage room.
In a tense scene on top of a staircase, the police arrive in time, Cleeve jumps out of his wheelchair, and the impostor dies after falling down the stairs.
This fundamentally uninteresting film tries hard to fill out its hour with unnecessary plot twists and a proliferation of characters.
But the basis of the story becomes clear after approximately ten minutes, and the two well-timed and genuinely frightening moments of suspense seem wasted on such a glaringly inadequate script.