In your sentence, Myly, "blind" works very well. A "lie" is just a false statement: Somebody asks me: "Did you eat all the cookies?"I say "no". That is just a lie. It's not a "blind" or a "ruse" because it is simple. I don't offer any false details.
A "blind" or a "ruse" is an elaborate lie. It is a story invented with details designed to make people believe that something is true that is actually false. Both "blind" and "ruse" imply a story designed to disguise the truth.
Actually, I find "blind" a little unusual here. It's understandable in context, but people would likely use these words instead: a cover story; a pretense; a ruse.
In my part of the world, we usually only talk about "blinds" when we are talking about places that hunters have camouflaged with branches so that they can ambush their prey: The hunters sat in the duck blind all day, waiting for the ducks to fly over them.