Room A4 (2) "Override"

The arrow on the left is surrounded by floor ridges and can't be moved. One particle is probably going to use it to turn towards the receiver above it.

There are actually two slightly different solutions to this puzzle. One of them gives the room its name.

Have you considered what would happen to an entangled particle if it passes over an arrow at the same time as its partner? Which direction would each turn in?

The answer is that arrows always take precedence, so rather than being redirected by its pair, a particle will always turn in the direction of an arrow it is passing over.

You can use this fact to solve this puzzle. Once the particles are split, you'll notice the right-hand particle needs to turn fairly soon, but this sends the left-hand one off course.

You can keep it on course by placing an arrow at the point it would deviate.

Split the particle left and right, in line with the fixed up-arrow. Redirect the right-hand particle upwards, but place a left-arrow to prevent the left-hand particle changing direction.