What does this simile mean? "The facts closed in on him like prison-warders handcuffing a convict. There was no way out...."I'm terrible at...

The trick to understanding the simile or metaphor is to visualize it. Place yourself in the convicts shoes for instance. Imagine yourself surrounded by prison wardens, say four to gain a good understanding, and they are all trying to handcuff you. The prison wardens are overpowering and may make you feel suffocated or trapped. Then compare that to facts overwhelming someone as if they were huge wardens with handcuffs, trying to trap you. Get the idea? The handcuffs symbolize constraints on the prisoner as the facts do on the main character. Remember: a simile is a comparison of two unlike things using the words "like" or "as".