Taking you through 1000 years of history in the space of just 500 yards, the Adventure Lab for which this is the bonus cache tells the story of Tempsford (Church End). For families (or big kids!), there is a nice playground to be found on the way and also a picnic area.
Once you have found each of the Adventure Lab locations, you will be given A, B, C, D or E which you then need to feed into the following to obtain the cache coordinates: N 52° 09.(C+E)CE W 000° 18.(A-C)(E-B-C)(C+D+E).
The walk to the bonus cache is not a long one.