"Logic was thrown out a long time ago."
Hekk is verse with negative zero dimensions that is always smaller than the (second) smallest verse. Since explaining things logically does not always end well (see Heck and Kceh), Hekk simply defies any and all traces of logic and ends up being whatever size it needs to be the smallest verse. It is contained by Hecc, and travels with it when Heck warps to another verse.
Hekks sometimes contain a Heaa, or even multiple.