The universes are expanding and contracting. Some increase in size,
others perish. Just like people and businesses. Universes are
connected by wormholes, or 'rotating black hole probabilities.' These wormholes not only connections from one universe to the next, they are also hailed as shortcuts for their ability to fold time and space. It is
only possible to travel through a wormhole if it is stabilized with
exotic matter; for these phenomenon are intrinsically unstable and
would be destroyed by our entrance.
But even if we could travel through a wormhole, the radiation would kill us.

The drawings are based on a basic Universe expansion cycle, and
illustrate the opportunities and perils of Inter-Universe travel.

Black holes can be deceptive. They are harmless, unless one gets too close, but if one does get to close the gravitational forces will tear them apart. Nobody in their right mind ever would go near one and so it is inevitable that a certain bate or siren lures travelers into black holes, and hence, to their doom.