The story
Metaphorically stretched taut, like a piece of cloth on a tenter (“a framework upon which cloth is stretched and dried”) secured by tenterhooks. First attested in the mid-1700s.
Etymology from Wiktionary, CC BY-SA 4.0.
on tenterhooks
on ten·ter·hooksToday it means: In a state of (great) apprehension or suspense; on pins and needles; on the rack. Full definition →