Object
Helix Corrosion Residue
Corrosive turquoise residue deposited by Helix energy attacks on organic surfaces during the Mandragora cult's woodland rituals
2 appearances
Purpose
To eliminate organic life while leaving material evidence of the Helix's passage through chemical contamination
Significance
This residue constitutes the first visible proof that the Doctor's negligence has unleashed Mandragora's threat into the medieval world. Its presence forces immediate confrontation with the consequences of his earlier actions aboard the TARDIS.
Appearances in the Narrative
When this object appears and how it's used