This month, the Evil Engineer comes to the aid of a correspondent set on very public revenge.

Dear Evil Engineer,

I hope you don’t mind a villain industry outsider writing to you with a very particular plea for help. I have spoken to friends, my sister and my therapist, and none of them have been able to give me what I need – so I’m reaching out to someone who might.

Earlier this month, I discovered my husband of 20 years has been having an affair. First came the denial, then the grief, then the resolution to give him what he deserves. I’m going to buy the biggest speaker system I can find – price is no object – and announce to the entire country that he is a cheating b*******.

Could you help me as the others have been unable to: by telling me how loud I need my system to be in order for the message to reach every corner of the UK?

Yours,

A scorned spouse

Dear scorned spouse,

I’m sorry to hear about your husband’s betrayal. Thankfully, it sounds as though you have found a healthy way to...