UNSC In Amber Clad

The  (FFG-142) was a United Nations Space Command Frigate.

It was also more simply known as the "IAC".

First Battle of Earth
As of October 2552, the In Amber Clad was captained by Commander Miranda Keyes. It was docked with Cairo Station during a posthumous award ceremony for Captain Jacob Keyes (The award was for Jacob Keyes but since he died on Halo it was given to Miranda Keyes), Sergeant Major Johnson and the Master Chief. In that ceremony, Miranda accepted a posthumous Colonial Cross for her father. In the middle of the ceremony, however, Covenant capital ships appeared around Earth and so the First Battle of Earth began.

Despite interference from Covenant Boarding Craft and Rangers, which were invading the station, Commander Keyes was able to reach her ship along with Sergeant Johnson. They got underway from the station and immediately descended to catch the Master Chief after his daring destruction of one of the enemy ships using their own bomb. Afterwards, the vessel descended to New Mombasa, where it dispatched Pelicans full of Marine and ODST forces to join the massive battle taking place around the city. The ship continued to unload forces and supplies throughout the battle, including Warthogs and Scorpions.

At the same time, the ship was picking up stragglers and wounded soldiers, including Johnson, the Chief, and the remains of Alpha Company of the 405th.

As the High Prophet of Regret suddenly initiated a Slipspace jump inside the city, the In Amber Clad was one of the only vessels close enough to follow it. The others were destroyed following the jump. Lord Hood allowed Keyes to follow the Assault Carrier through the Slipspace rupture, even though she did not know where it was headed.

Battle of Installation 05
The In Amber Clad ended up at Installation 05. There, Keyes immediately sent the ODSTs and John-117 to the surface in Human Entry Vehicles to track down the Prophet at The Temple, while she herself took Johnson and most of the Marines to the Library in order to retrieve the Index and prevent the Covenant from activating Halo.

Though the Spartan succeeded, most of the ODSTs perished in the fight. As Keyes entered the Library, they were immediately attacked by the Flood and most of her Marines became Combat Forms and Carrier Forms, only a few eventually making it to the index. However, Keyes, Johnson, and what was left of the marines were ambushed by the Arbiter only a few seconds after retrieving the index.

It is likely that the Flood commandeered a Pelican and infiltrated the In Amber Clad, as it was not seen again until it crashed into High Charity. At this point the Flood controlled the ship. It is speculated that Gravemind was aboard. The ship crashed into a tower near the Council Chamber and immediately the Flood used most of the ship's remaining Pelicans to spread out over High Charity, often crashing the ships to inflict maximum damage on the city. The Flood quickly assimilated most of High Charity's population. At this point, the ship was out of commission, designating it as destroyed.

Cortana intended to use the In Amber Clad's engines to destroy High Charity, but it was never done. It is unclear whether she still could do it because during the Battle of Installation 00, Cortana is unable to stop the Gravemind from using High Charity to travel the galaxy. It is assumed to be destroyed when John-117 blasted the station's reactors causing them to go critical.

Trivia

 * In Halo: Ghosts of Onyx, the In Amber Clad was once referred to as a destroyer, however, because the ship carries the FFG hull classification, it is designated as a frigate.''