Caught (There are many kinds of prisons.)
Don knows that nothing good ever comes from a silent lair. It means that at least one of his brothers is badly injured and the others are upset. Silence means Master Splinter is tending the injured or lying sick in his own bed.
Worse, it means there's nothing else he can do. Don will find himself unable to focus. His thoughts will swirl through his mind, creating a maze for which he has never found the exit. Trapped, he will have to wait for the soft sound of footsteps and a brother's hand on his shoulder to set him free.