Mary’s execution shortened Drake’s next venture to Cadiz.

Evidence

Plans for Drake to return to the West Indies, possibly with the help of the Dutch, were being made that autumn. These were abandoned, however, when the execution of Mary of Scotland heightened the threat of a Spanish invasion, and the departure of a fleet for so extended a voyage became unthinkable. Drake’s range then was shortened to Cadiz. — Mary Frear Keeler, Sir Francis Drake’s West Indian Voyage,…, 127

Categorization

• XREF: Directly feeds the reader’s ‘English Armada / Cadiz fireship’ storyline — the political trigger that made Cadiz the target instead of the West Indies.
• SEED: Angles the narrative: the execution of Mary of Scots rerouted Drake’s war westward to Cadiz — a causal hinge worth dramatizing.
• corroborated: 2 independent passages support this claim — Mary Frear Keeler, Sir Francis Drake’s West Indian Voyage,…, 127