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Object
Object

Acetone Solvent Cylinder (Polly's Formula)

A repurposed glass cylinder originally removed from a dismantled fire extinguisher in the Control Room, filled with Polly's acetone-based solvent. The cylinder is manually transported through sealed airlocks to avoid solvent evaporation in the lunar vacuum. Ben Jackson uses it as an improvised weapon, hurling it at a Cyberman's chest unit to shatter the container and release corrosive vapor that dissolves the Cyberman's metal plating. This tactical maneuver incapacitates the target, marking a brief but critical victory during the moonbase siege. Polly Wright observes the process with concern, while Roger Benoit remains captive during the operation. The cylinder's glass construction ensures the solvent remains contained until impact, where it delivers a decisive blow against the Cybermen's vulnerability to acetone.
2 appearances

Purpose

Deliver acetone-based solvent to Cybermen in space vacuum without evaporation

Significance

Ben's improvisation exploits Cybermen vulnerability, marks his shift to aggressive risks for Benoit's rescue, and delivers brief tactical win amid moonbase siege

Appearances in the Narrative

When this object appears and how it's used

2 moments
S4E25 · The Moonbase Part 3
Ben prepares solvent weapon for vacuum

Polly’s acetone-based solvent is the moonbase crew’s only known weapon against the Cybermen. Ben fills the glass cylinder with this corrosive liquid, which will dissolve the Cyberman’s chest unit upon impact. The solvent’s effectiveness is proven, but its delivery is the challenge—it cannot be sprayed in the vacuum, so it must be carried manually. This object is the heart of the plan, the one thing that can turn the tide against the Cybermen. Its presence in the scene underscores the high stakes: without it, the Cybermen would be unstoppable, and Earth would be doomed. The solvent’s role is both a scientific solution and a narrative lifeline, representing hope in the face of overwhelming odds.

Before: Stored in the Control Room, ready for use but not yet deployed. It is a clear liquid, its potency known but its delivery method still uncertain until Ben’s improvisation.
After: Sealed inside the glass cylinder, carried by Ben into the lunar vacuum. Its fate is now tied to the cylinder’s survival—if it reaches the Cyberman, it will save Benoit; if not, the Cybermen’s plan will proceed unchecked.
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S4E25 · The Moonbase Part 3
Ben’s solvent attack on a Cyberman

The solvent-filled glass cylinder is the improvised weapon Ben uses to exploit the Cybermen’s vulnerability to acetone. He hurls it at the Cyberman’s chest unit, shattering the glass and releasing the corrosive vapor that begins dissolving the Cyberman’s metal plating. The cylinder’s sturdy glass construction ensures it survives handling until the targeted strike, where it fulfills its critical role in disabling the Cyberman. Its use is a testament to human ingenuity in the face of overwhelming mechanical threat.

Before: Filled with Polly’s acetone-based solvent, securely held by Ben in the airlock, ready for use as an improvised weapon.
After: Shattered upon impact with the Cyberman’s chest unit, its contents released and the glass fragments scattered on the lunar surface. The cylinder is destroyed in the process of fulfilling its purpose.
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