Cyber-Lieutenant

A Cyber-Lieutenant was a rank in the leadership hierarchy of the Cybermen, particularly the CyberNeomorphs. They served as the assistant to their Cyber-Leader and third-in-command of the Cyber-Force. Unlike the majority of Cyber-Leaders, Cyber-Lieutenants had no unique physical characteristics to distinguish them from standard Cybermen.

A Cyber-Lieutenant always remained close to its Cyber-Leader during missions, and tended to be more cautious than their Leader, often highlighting the drawbacks to their Leader's planned course of action. However, despite the Cybermen supposedly being a purely logical species, Cyber-Leaders would sometimes use their higher rank to ignore the advice of their Cyber-Lieutenants; for example, when one Cyber-Lieutenant objected to its Cyber-Leader making inaccurate reports to their Cyber-Fleet, the Leader told it that "[it was] outside [its] function."

The Mondasian colony ship
A Cyber-Lieutenant, evolved from one of the hundreds of Mondasian Cybermen created on Floor 1056 of a Mondasian colony ship, (TV: The Doctor Falls) served as second-in-command to a group of CyberNeomorphs sent from said floor to Floor 0508 of the ship. Under orders from a Cyber-Planner, they attempted to prime a group of Cybermats to attack Floor 0507, as well as capture and  for interrogation to learn as to how and why the Cybermen's definition of humanity had been altered, and who had done so. However, before the patrol trapped the trio, Missy stunned the Cybermen with her sonic umbrella, allowing the Master to destroy the Cyber-Lieutenant with a direct blast to its chest plate from his laser screwdriver. (PROSE: Alit in Underland)

Start of the Cyber-Wars
In the 26th century, a Cyber-Lieutenant accompanied a Cyber-Leader on the latter's plot to destroy Earth with a Cyber-bomb to prevent an alliance forming. The bomb failed thanks to the Fifth Doctor. The Lieutenant and the Cybermen were able to infiltrate Briggs' freighter. Its cargo, unknown to the crew, was an army of Cybermen. They awoke and took over the ship. The Cyber-Leader planned to destroy life on Earth by hitting it with the craft they had reprogrammed. After the Doctor killed the Cyber-Leader, the Cyber-Lieutenant was killed by Nyssa on the TARDIS. (TV: Earthshock)

Attempting to save Mondas
In 1985, a Cyber-Lieutenant acted as second in command to the Cyber-Leader in their base in the London sewers on Earth, and also acted as the Cyber-Controller's adviser and reporter. (TV: Attack of the Cybermen)

Pursuing the Nemesis
An Isomorph Cyber-Lieutenant in 1988 assisted a Cyber-Leader in their attempt to acquire the Nemesis. With a fleet of thousands of Cyber-Warships, the Cybermen intended to conquer Earth and turn it into New Mondas. This Cyber-Lieutenant encountered the Seventh Doctor, and objected to its Cyber-Leader making reports to the fleet, although the Leader ignored it. The Cyber-Lieutenant, along with another Cyberman, attempted to harm Ace, but were killed when the Rocket-sled's engines fired at them, burning them. (TV: Silver Nemesis)

In the Death Zone
A Cyber-Lieutenant, along with a Cyber-Leader and a squad of CyberNeomorphs, was Time Scooped by Borusa to the Death Zone in a round of the Game of Rassilon. When the Cybermen discovered the Fifth Doctor and, they attacked the duo in an attempt to capture them, although the Doctor escaped with the Master's teleport device (TV: The Five Doctors) into the Death Zone's pocket dimension, (AUDIO: The Five Companions) while the Master tricked the Cybermen into working with him. The Master led a group of the Cybermen to the Dark Tower, where they attempted to cross a chessboard-patterned floor and were all electrocuted, save the Master. Meanwhile, the Cyber-Lieutenant and the other Cybermen placed explosives around the Doctor's TARDIS to destroy it; however, the TARDIS safely dematerialised before the explosives could be detonated. (TV: The Five Doctors)

Behind the scenes

 * The First Cyberman, a CyberNomad, held a position equivalent to a Cyber-Lieutenant in TV: Revenge of the Cybermen, before Cyber-Lieutenants were first introduced in TV: Earthshock.