Atlantis.

It is the only forbidden sector on Skywatch star maps. Declared off-limits by high-ranking admirals with no explanation. What is known about the gruesome disaster aboard the Achaen Science Station and the ensuing clash between hostile deep space war fleets raises more questions than answers.

Now, after decades of silence, the cryptic signals are back, and even the supermassive Omicron 474 singularity can't shield Core space from what is almost certainly a new and alarming threat. Either the Kraken Decarchy is planning a fresh round of subterfuge, or a third faction may be prepared to take advantage of the conflict over Mycenae Ceti Four and launch an offensive against both the Sarn and the Alliance.

Admiral Benjamin Powers, CINC Southern Banner, risks a court-martial and surreptitiously orders Captain Jason Hunter, his senior officers and an elite marine special forces unit to investigate the Atlantis frontier. Less than 48 hours later, Admiral Neela Hafnetz, Flag of Strike Fleet Achilles, intercepts Argent's battle group and orders Hunter to stand down.

The captain refuses, citing his orders. He skillfully keeps Powers' name out of the dispute, but that does not satisfy Admiral Hafnetz. A standoff ensues. When Hunter tries to evade the Achilles formation, the heavy battleship Saint Lucia opens fire!

According to the sensor logs of the Saint Lucia, and the report of Admiral Hafnetz, Argent was disabled in the engagement. With Hunter still in command, she was last seen as she crossed the Omicron 474 event horizon.

DSS Argent was reported lost with all hands.

...two days later, Captain Hunter learned the real reason Atlantis was declared forbidden.