-ensis

There’s the satisfying meat and potatoes of exploration at Castle Ensis, with vertiginous balustrades and winding ramparts that cross over and under themselves in impossible architectural configurations.

The shell of Ensis directus really does look like an old-fashioned straightedge razor, narrow and thin, or a jackknife, per its other common name, Atlantic jackknife clam.

The Atlantic razor clam, Ensis directus, has been dubbed "the Ferrari of underwater diggers".

Quantumcunque ferox tuus hic, Petre, fulminat ensis, Tu tibi jam pugnas, � bone, non Domino.

—ENSIS asks, "What is the usual test of a good blade?"