You are in the lakesides of Europe, 127 million years ago.

The damp fern forest of the early Cretaceous was quiet, save for the rhythmic thwack-hiss of thick vegetation being sheared. You froze behind the mossy trunk of a cycad, checking your surroundings.

About twenty feet away, a four-metre-long Polacanthus was grazing.

It didn't look like the agile predators you had been avoiding. It was low to the ground, a walking tank covered in light brown osteoderms—bony plates embedded in its skin. Its back was a defensive fortress, culminating in a striking, shield-like sacral shield over its hips and a row of sharp, menacing spines along its flanks.

As it moved, you heard the rustle of its dark armor. It seemed oblivious to you, entirely focused on feeding on low-lying plants. You watched as it braced itself with its heavy tail, acting like a living, armoured lawnmower. While its small, bird-like head looked almost timid compared to its massive body, the sheer weight of its armored flanks made it clear that nothing in this swamp would want to tackle it head-on.