Master's Sea Devil Sonar Control Mechanisms

The button near the intercom grille is pressed by the Master after Trenchard departs, triggering a hidden mechanism that summons a guard into the cell. Unknown to the guard, the button functions as a mechanical trigger for the Master's trap, ensuring the Doctor's intended solitude.

The deceptive call button in the Master’s cell appears innocuous but is revealed by the Master’s manipulation of Trenchard into pressing it unknowingly, triggering the Doctor’s trap instead of summoning aid.

The Master’s device is consciously picked up and carried as he responds to Drew’s summons. Its unseen purpose contrasts with Drew’s mundane understanding of it as a mere item.

The device, initially described as a communication replica, becomes the focal point of Trenchard's anxiety and the Master's reassurance. Its pending completion and function as a trap illustrate the Master's deception, binding Trenchard's fate and perceived reward to its success or failure.

The Master references the device as a ‘perfect replica of the communications device used by the enemy agents,’ implicitly elevating its importance as a lure in the trap. Its imminent readiness is used as both reassurance and lever to command Trenchard’s compliance and urgency.

The Master activates his hidden containment signal device, causing a small spinning dish to broadcast an invisible net across the beach and minefield. This technology transforms open pursuit into a precision trap, allowing a single, unified capture operation to ensnare all three targets at once.

The Master activates the Master's Containment Signal Device, a hidden mechanism disguised within the Governor's Office. The spinning dish broadcasts an invisible containment field that entraps anyone within its range, forcibly drawing the Doctor, UNIT personnel, and Jo into close proximity. The device's true deadly function surpasses Trenchard's expectation, transforming the pursuit into a systematic containment.

The Master’s remote control device, operated unseen in his hand, transmits amplitude-adjusted commands to the Sea Devil through the transmission collar. Its unassuming interface belies its power to turn a rampaging beast into a directed weapon, enabling the Master to orchestrate the assault with chilling precision.

The Master references the device as both justification and shield, framing his manipulation of reality as a technical necessity. Trenchard’s inability to comprehend or challenge its purpose underscores the device’s role as a lever of coercion, its perceived power elevating it to the heart of their standoff.

The device emits sped-up alien transmissions detectable by nearby personnel, functioning as both a technological ruse and a control mechanism. Initially unplugged by the Master to disrupt the signal during Trenchard’s presence, it is reactivated afterward to broadcast the final commands. Its transmission accelerates until it synchronizes into a command sequence for the Sea Devils.

The concealed transmitter pulses to life as the final key is pressed, emitting a tight-beamed coded burst that overrides the Sea Devils’ dormant instincts. It shifts from a dormant state of concealment to active transmission, its metallic casing humming faintly as the signal arcs across miles of ocean to awaken its targets.

Concealed in the Master’s grasp, the device hums subtly as its signals override the Sea Devils’ instincts, turning living weapons into puppets for his will. Hidden from Trenchard until revealed on the monitor, its activation accelerates the fortress’s collapse, with melted locks and shattered defenses bearing silent witness to its terrifying influence.

The Master manipulates his remote control device in a concealed corridor, its unassuming interface sending lethal commands to reptilian operatives. The device’s presence enables expansion of chaos while the Master remains unseen, turning organic predators into extensions of his will.

The Sea Devil Reactivation Trigger Mechanism is referenced as faulty by the Master during negotiations with the Sea Devil leader. Though not physically present, it becomes a critical plot device driving the Master’s demand for electronic equipment from humans, revealing his plan to manipulate the reactivation unit and prolong the conflict under controlled conditions.

The Sea Devil's reactivation trigger mechanism is referenced as faulty by the Master, who uses this flaw to justify his demand for electronic equipment. The mechanism functions as a narrative device enabling the Master’s manipulation, tying the alien's survival to his hidden agenda.

The sonar control device is referenced through the Master’s explanation of the trigger mechanism’s purpose, though it remains unseen in this scene. Its mechanical hum and circuit flaws are inferred indirectly via the Doctor’s observations and the Master’s claims. The device embodies the central artifact of the episode’s conflict.

The Master attempts to activate the control device, projecting signals to the Sea Devil bases, but it fails due to the Doctor’s sabotage. The Doctor claims to correct the fault by reversing the input and output jacks, feigning technical incompetence while ensuring the device remains inoperative despite appearances.

The Master's sonar control device becomes the focal point of the sabotage crisis as the Doctor's reversal of input/output connections causes system overload evidenced by noise and flickering lights. The Master's attempt to demonstrate functionality fails, forcing him to physically unplug power to silence the alarms temporarily.

The mechanism is inserted and operational in the Master’s escape craft, linking the Sea Devils’ activation system to his flight plan. Though not visibly used in this segment, the mechanism’s presence justifies his haste and foreshadows his next actions, bridging his escape attempt with the unholy awakening of his reptilian allies.

The Master uses this device to trigger the Sea Devils' reactivation process, only to discover it has been sabotaged by the Doctor, causing the device to emit reverse feedback and trigger the base’s self-destruct mechanism.

The Master presents the trigger mechanism to the Sea Devil commander and activates it, believing it will fully reactivate the Sea Devil hibernation systems. The Doctor reveals he has reversed its polarity and incorporated a self-destruct sequence into the main control switch, rendering the device inert and ensuring the base’s destruction.

The Master clutches the Sea Devil Reactivation Trigger Mechanism, its crimson flickers now erratic under the Doctor’s sabotage. The device’s scorched casing bears silent witness to the Doctor’s earlier interference, its fabricated authenticity collapsing under technical scrutiny.