Abstraction

Secret removal, especially theft.

Abstract- (verb when used with an object)

Abstract- means to draw or take away; remove.

-ion

-Ion means denoting action or condition.

Explanation

Abstraction means a secret removal because abstract means to remove and -ion means a mark or sign of an action or condition such as a secret condition.

Sentence

They carried out an abstraction of the Mona Lisa right under the security guard's nose!