The Endeavour has entered a pocket universe through a portal with their shields up and has shrunken to the size of 2 cm. Outside the portal, 3 large enemy war ships are waiting for them, two Cardassian ships Galor class and one Romulan war bird. They do not dare to enter, because their shields do not correlate with the protal and they would be crushed.

The simulation of what would happen if the Endy went back to normal space without shielding showed, that they would get back through unscathed and without changing size back to normal. Their shields not only let them pass through, but they also reacted with the portal in a way that influenced their size - getting smaller once they entered this tiny pocket universe - and getting bigger once re-entering their normal-sized universe. Without shields they could still go through, but not change size in the process. Apparently their enemy ships had not even thought of dropping their shields, otherwise they might make the passage too.... without changing size and hence being able to be a giant ship in this pocket universe, and able to wreak extreme havoc.