The first novel in what was to become known as “The Helena Trilogy” was not planned by the author, Pamela Hansford Johnson, as the first in a series. If it had been, the sequence might have been labelled the “Pickering Quartet”, since Claud Pickering is the first person narrator of the three novels under discussion – Too Dear for My Possessing (1940), An Avenue of Stone (1947) and A Summer to Decide (1948) – and he and members of his family also appear in relatively minor roles in Johnson’s Winter Quarters (1944).
Pollard, Wendy. "The "Helena Trilogy": Too Dear for My Possessing, An Avenue of Stone and A Summer to Decide". The Literary Encyclopedia. First published 30 May 2015
[https://www.litencyc.com/php/sworks.php?rec=true&UID=35634, accessed 21 February 2018.]