Room B4 "Tunnel"

You're given a two-way arrow immediately in this puzzle. That's a fair indication that entanglement is going to be involved in the solution.

You don't have any down-arrows, so you can't make the particle pass through the force-field that way. How else might it be possible?

What usually happens to a particle when its entangled pair passes over an arrow?

It usually changes direction, right? But if the first particle is already going in the direction of the arrow, nothing happens. Or does it?

What would happen to a particle if an arrow forced its pair forward, in the direction it's already going? Particularly if that particle couldn't continue forwards itself?

Try to force a particle through the force-field via its entangled pair.

Line up the up-arrows so that the right-hand particle passes over one just as the left-hand particle encounters the force-field. The particle will "tunnel" through the barrier.