bridge the gap

a bridge too far

A step or action that is too ambitious; an act of overreaching.

bridge over troubled waters

Someone or something that provides support, comfort, and a means to overcome difficult times.

burn that bridge when one comes to it

To anticipate dealing with a problem or situation either by acting in a manner that alienates or cuts ties with others, or merely with the expectation of encountering trouble.

cross that bridge when one comes to it

To deal with a problem or situation only if and when it arises.

I have a bridge to sell you

An indirect way of expressing that the addressee is gullible.

stand in the gap

To expose oneself for the protection of something; to make defence against any assailing danger; to take the place of a fallen defender or supporter.

water under the bridge

Something in the past that cannot be controlled or undone, but must be accepted, forgiven, or forgotten.