5.1: Intelligence

Although the Potting Shed is hidden behind a shrubbery in the grounds of an abandoned country house, and thus very much off the beaten path, it faces a twice yearly danger. It turns out that it lies on the biannual migration path of the rare but ferocious bulb spider. Such is Alcock’s concern with this that, until the sudden need since last year to tutor Lottie, the only task he has asked the Potting Shed’s resident boffin Hipparchus to undertake was to track the migration pattern and predict when they should be on the alert as the spiders make their way north to Scotland, in early summer, and south again, at the start of autumn.

Using both weather data from the Met Office and an informal network of bulb spider watchers linked together by short wave radio, Hipparchus offers a weekly briefing to the Chairman as to the danger. It’s been suggested that, only by being born too late, he was Bletchley Park’s great loss. 

Today the risk has reached the second highest level: ‘extreme’. 

Alcock warns Masongill of this before he sets off for his nightly outdoor watch of the surroundings.