Heavenly Host

The Heavenly Host, or the Host, were service robots working for Max Capricorn Starcruisers. They were fashioned to look like angels. Their purpose was to provide information and other assistance to crew and passengers. However, the Heavenly Host lacked autonomy and would do anything their master authority ordered, including criminal acts such as murder.

History
Under the command of Max Capricorn himself, the machines turned deadly. They killed many of the passengers and crew of the Starship Titanic in 2008 as part of Capricorn's scheme to destroy his own ship and then retire a wealthy man.

Some of the Host were destroyed by an electromagnetic pulse set off by Bannakaffalatta, who used the last of his cyborg body's energy at the cost of his own life.

After Max Capricorn was killed by Astrid Peth, the Host reverted to the next highest authority figure, the Tenth Doctor, helping the Doctor reach the bridge of the ship to save it. (TV: Voyage of the Damned)

Technology
The Host had a monotone voice and started sentences with the word "information" when answering a query.

Security Protocol One allowed the person who executed it to ask three questions, which would temporarily override whatever other command the Hosts were executing until the three questions were answered. Additionally, at least one of the Host could be diverted from its current orders for a few seconds when the Doctor asked it in a raised voice: "Information override. You will tell me the point of origin of your command structure." The Host complied, answering with: "Information: Deck 31."

Each Host had a hinged jaw, which moved when they spoke.

When given the command to commit murder, they would repeat the word "kill" numerous times.

Each Host used a single Halo, mounted on struts protruding out of their heads, as a weapon, which they threw at enemies, causing great harm with its razor-sharp edges. If deflected, they would return back to the Host, which would be able to catch and throw it again and again. Without a halo, the Host would resort to hand-to-hand combat, consisting of strangling a human by grabbing their neck and striking with their metal hands.

They were capable of flight, which their wings would unfold to do. An individual Host had the strength of ten men.

Each Host had a button on the back of their neck which would switch them off, making them rigid. At least when switched off, one could be carried and moved with ease with two humans holding the legs and two holding the torso.

Behind the scenes

 * The Heavenly Host were voiced by Colin McFarlane.
 * A free printable Heavenly Host Christmas tree ornament was featured in the 2007 Adventure Calendar.

The Visual Dictionary
The non-narrative source Doctor Who: The Visual Dictionary gave further information about the Heavenly Host: their metal hands could be used for dishing out karate-style blows to others, and their default position was standing upright with their hands in the prayer position.