the position of the mystery ship and to tell accurately the distance
between the two vessels.

"Reckon he'll be dead off our bow in a minute or so," observed Cleary
as he completed another observation based on Smith's latest report.

McClure sprang again to the periscope.

"Yes, we ought to get a line on him soon enough now," was his rejoinder.

For a moment the two officers studied the haze of the night sea
around them, unable yet to discern the form of the approaching vessel.
And then came a huge specter, looming up directly off the starboard
quarter of the _Dewey_ in the proportions of a massive warship.

"Looks like a German cruiser," said the American lieutenant as he
gripped the brass wheel of the periscope and gave himself intently
to the task of divining the identity of the unknown ship.

Cleary was making observations at the reserve periscope, the two
officers having plunged the conning tower of the _Dewey_ in utter
darkness that they might better observe the shadowy hulk bearing
down upon them.

"It is a German cruiser---_Plauen_ class---and coming up in a hurry
at better than twenty knots," exclaimed McClure, as the outline of
the ship was implanted clean-cut against the horizon dead ahead of
the _Dewey_.

His hand on the firing valve, the submarine commander waited only until