Cassandra Cain's strangest ability

We all know Cass can read an opponent's body language and use that info effectively to predict his or her next move in a fight.  That's pretty strange.  But that's nothing compared to her ability to street ski while being towed by a moving car, as she does in Batgirl #48 (March 2004).

In her boots.

With no wheels of any kind on her feet.

She also appears to violate several laws of physics before she does that, but it's drawn a bit obscurely.  We'll discuss this in a little more detail later.