We know who the spy is though, the doctor Bord (Noel Willman), who plans to steal M7 and Michael along with it. After a near disastrous first flight, he manipulates Michael into taking him with him on an unauthorised second flight and that is when he will strike...
The film isn't sure what it should be. It could be a spy drama, aviation adventure or melodramatic romance and if it had chosen one of those and stuck with it it probably would have been an excellent film. Unfortunately it tries to be all three with varying degrees of success.
The special effects with M7, which is a classic British 1950s style vision of the future of flight (basically a Victor bomber with nuclear engines), are pretty good. The tension, when it is there, is good. The padding kind of ruins things a bit, but overall a decent watch.
