A Hypothetical question for every videographer here!

So hypothetically speaking, if someone decided to make a film but then realized they spent all their money on just about everything for the film but a good cine lens. And all they have a telephoto lens and a factory 18-55mm. Uhh hypothetically, what lens would you recommend for them to buy to use for these short films they want to shoot whether indoors or outdoors like a great little “go-to”?? Hypothetically this guy might be me