He had first seen Dr. McKay two years ago. McKay hadn't noticed him then - he was too busy trying to prove he was the foremost expert in wormhole physics.
McKay had got back from visiting Cheyenne Mountain and was full of stories about Samantha Carter and her ignorance. Though the doctor was also at pains to make everyone aware that he still lusted after the 'dumb blonde'. Caldwell was of the opinion that the Doctor doth protest too much.
They went their separate ways - McKay to Russia and Caldwell to a top secret project far away from Area 51.
When he discovered there was a chance to see McKay again - or, officially, a chance to work in another galaxy, with his own command - he applied immediately.
It didn't work out quite how he hoped - but as a consolation prize he was offered the command of his own ship - and the opportunity to get to know McKay on one of the shuttle journeys to Atlantis.
He went all out to get to know the man properly on the first trip out from Earth - the third trip between galaxies for Caldwell himself. There were weeks to kill and he was sure he could become more closely acquainted with McKay during the lulls.
But still McKay was oblivious. If the man wasn't such a genius Stephen Caldwell might say he was obtuse.
Glances didn't work, flattery didn't work, not even the most direct come ons he could muster made any impact at all.
He was beginning to despair.
And he was also beginning to suspect his jealousy of John Sheppard was more than justified. Not only had the man got his command, he seemed to be more than usually close to McKay.
Which was why the email he got from the good Doctor after the whole sorry blowing up a solar system incident had been so very precious.
It gave him some hope.
It wasn't exactly an admission of love, but he was sure he could read between the lines
Dear Colonel Caldwell,
It's been wonderful working with you these last few months and may I just say that we all admire your fortitude and dedication to your job.
I would just like to convey my deep gratitude for your actions re: the Arcturus Project incident.
If you had not been there to help then the Lt. Col and I would almost certainly have perished.
You have enabled me to do my job and supported endeavours completely these last few week. Thank you for trusting me, and I hope this little incident has not bruised the faith you have shown in my work.
I have apologised to many of the Atlantis staff, and I owe you too an apology - thank you for not going out of the way to make me feel guilty about the whole thing; even if it was essentially my fault (I will not allow anyone else to be held accountable for my actions or scapegoated in any way. Even so, I appreciate your help. I hope in future I can repay your faith in me).
Thank you again. I would not be here without you.
Rodney McKay (Doctor)
He gave it a few days before replying - but he couldn't help but hope McKay would read between the lines of his missive.
I was just doing my job.
Perhaps he had said too much.