Find lines from Macbeth to prove that the news of Fleance's escape fills Macbeth with terror and fear.

The scene you want to examine closely to answer this
question is Act III scene 4, which is when the Murderers return and tell Macbeth about
the success and failure of their mission just before the banquet that Macbeth has with
his lords. It is clear that Macbeth responds to the news of Fleance's escape with fear
and terror from the kind of language that he uses to describe his feelings. Note what he
says:

Then
comes my fit again: I had else been perfect;

Whole as the
marble, founded as the rock,

As broad and general as the
casing air:

But now, I am cabin'd, cribb'd, confind'd,
bound it

To saucy doubts and
fears.

Consider the whole
list of adjectives that Macbeth uses to describe his feelings now that Fleance is free.
Each of theme describe a feelign of entrapment and of restriction as he is now subject
to "saucy doubts and fears" that threaten the security that he was hoping to achieve
through eradicating Banquo and his line and thus making the prophecy of the witches
impossible to fulfill.