Two immense orbital railguns thought scuttled beyond use are secretly restored and used to smash Victra's north-pole fleet with a pre-calculated storm of corvette-sized slugs.
The Twins of South Pacifica are a pair of elephantine orbital railguns once controlled by the Republic, then scuttled before the enemy seized them. Atalantia and Atlas's forces could see their distant glint from Earth, but Republic command believed neither the Core nor the Rim possessed the technology to return the weapons to effective service.
That assumption collapses at Mars. After hours of enemy maneuvering, the restored Twins fire a broad, pre-aimed stream of corvette-sized durosteel slugs along the path Victra's Task Force Spear has been led into. The barrage tears through battle stations and ships at the north pole, using metal apparently stripped from the White Fleet and arriving too fast for a meaningful response. There can be no immediate second shot at such expense, but the strike has opened the battle and exposed Phobos to Lysander's next move.
A paired installation of colossal orbital railguns capable of launching corvette-sized solid durosteel slugs at extreme velocity across interplanetary distance.
The Twins are the enemy's shock weapon in the attack on Mars, proving that supposedly neutralized Republic infrastructure has become a devastating vulnerability.