Festung The Fortress

The other German troops have pulled out.

They left behind some anti-tank guns and a few infantry.

Not enough operational prime movers for all the guns.

So they stay behind.

And delay the Ivans.

While their friends make it over the next river bridge.

And blow up that bridge before the Ivans can catch up.  While these men stay behind in a festung to try and slow down the Russian steamroller long enough.