Put the verbs in the story in the Past Simple or Past Perfect Tense.

As the UFO’s door (to open) and a small silver-suited figure (to appear) the police (to get) frightened. But then a famous British businessman Richard Branson (to come) out of the UFO. It (to turn) out that it (to be) his April Fool’s Day practical joke and he (to think) it was one of his best. Trying to combine his passion for ballooning with his love of practical jokes, Branson secretly (to build) a hot-air balloon that (to look) like a UFO. He (to be) sorry that the poor weather conditions (to spoil) his original plan to land in Hyde Park. At first, the police (to see) the funny side of the joke, they (to be) angry with the prankster and threatened to arrest him but later they (to join) in the laughter.