Hampstead Heath is both the reported launch site of Birdlip’s dirigible and the place William Keeble expects it may return to as its engine fails. The possibility turns the Heath into a prospective rendezvous: Keeble urges his companions to meet the craft there and take the box it carries before Ignacio Narbondo can claim it.

Launch Site and Projected Return

Keeble connects the Heath to the dirigible’s unusual course. He recalls that its passage five years earlier was exceptionally low and far north of its 1865 passage. From these observations, he suspects that the engine is declining and that the craft may soon descend. Although it could fall into the sea, he thinks it is tending toward Hampstead Heath, where it was launched.

Keeble attributes this possible return to a homing tendency in the engine, which he believes arose accidentally from its design rather than from any intention of his own. The Heath is therefore more than a point on the dirigible’s route: in Keeble’s account, the machine’s origin may also determine its destination.

The Proposed Interception

When the group considers what to do if the dirigible comes down, Keeble recommends meeting it at the Heath and taking the box. He argues that the companions together could manage the seizure, then proposes disposing of the box in the Thames at Westminster Bridge. His reasoning is that the being inside it must breathe and could be drowned; he also expresses a desire to keep it from Narbondo and anger over what it did to Sebastian Owlesby.

This is a plan, not an event shown in these passages. Keeble speaks of the landing as a likely future possibility, and the proposed encounter makes the Heath the intended site of a contest over the box.

Narrative Significance

The Heath’s importance rests on the conjunction of launch and anticipated return. An unintended feature of the engine’s design gives the place a new strategic role: Keeble’s reading of the dirigible’s motion leads him to direct the group there, where they hope to intercept it. The location consequently anchors a plan shaped by both scientific speculation and personal grievance, while the possibility that the craft may instead fall into the sea leaves its return uncertain.