Imagine a PotterWhoLock crossover:

Harry: "We need to destroy the horcruxes!"

Doctor: "Horcruxes? Why don't we all go to Mars for the day? You'll be gone 2 minutes, tops."

Sherlock: *groans* "What does that matter? No one needs to know that we spin around a big ball of fire -"

Doctor: "Technically it's a nearly perfect spherical ball of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process."

Harry: "Guys -"

Sherlock: "No one cares! There are perfectly more knowledgeable things to fill your head with, less of the ordinary rubbish and more of what matters! Why would it matter whether we orbited the moon, or a planet-shaped solid gold model of a chicken -"

Ron: "Did someone say chicken?"

Doctor: "But it's the solar system!"

Harry: "Is anyone even listening to me?!"

Merlin: *pops head out a bush* "I am, Harry."

*silence*

Arthur: *drags Merlin away* "wrong crossover, Merlin."

(A/N - This was really rubbish but I wrote this very quickly okay don't judge me.)