Swallow watch, Part One

Our recent holiday to Northumberland was a wonderful experience.
To cap it all, in the car port of our accommodation there was a Swallows nest, with what I thought had four chicks over a week old, but a fifth was hidden and clearly the runt of the litter. We feared it wouldn't survive.
We watched them grow over the following week of our stay, with their parents ever attentive despite a couple of days of poor weather.
This is the first part of three instalments of their story..