Mace's Polygrite Bracelet

Mace wears the polygrite bracelet, which draws the Doctor’s attention when he inquires about the ornament around Mace’s neck. Nyssa identifies it as polygrite alien tech, confirming its extraterrestrial origin and linking it to a larger conspiracy involving a possible alien crash.

Though Mace wears the polygrite bracelet throughout, it is not handled during this event. Its existence in the scene symbolically connects to the power packs and Mace’s earlier mention of the comet. The bracelet's alien origin corroborates the power packs’ technological nature, reinforcing a hidden narrative of alien presence.

Mace’s alien bracelet fragment becomes the Doctor’s key to reclassifying local events as extraterrestrial when handed over. Its intricate glyphs and density confirm non-terrestrial manufacture, prompting the Doctor to shift focus from plague to cosmic conspiracy.

Tegan’s Polygrite bracelet is pried open by the Doctor and the embedded Terileptil powerpack torn out in one movement. The alien metal’s glyphs gutter as control drains, and the bangle falls slack around her wrist, its cold bite replaced by sudden exposure to freedom. The sudden void leaves Tegan collapsed and disoriented.

Mace's Bent Safety Pin becomes the crucial tool in bypassing the forcefield's control. Its inclusion in the circuit tricks the system into believing the switch remains closed, allowing the forcefield to deactivate long enough for escape.