Just how Sparks are able to warp the laws of time and motion (among others) has never been successfully analyzed. People who try to carefully watch them report suffering a sort of cognitive dissonance where they simply cannot remember what happened even though it happened right in front of them. These, as it turns out, are the lucky ones, as most people who get too close to a Spark who is happily building something tend to wake up and realize that they have become components.

Phil Foglio (b. 1956) American writer, cartoonist

Agatha H and the Voice of the Castle (2014) [with Kaja Foglio]
    (Source)