Definitely a poignant and bittersweet story, as befits the subject and title. One wonders what would've happened if they'd managed to find a way before Severus took the mark? Of course, one also wonders if he'd've taken the mark if the Marauders hadn't pranked him so much, though I suspect there are other complications there, too.
Author's response
Thanks =). I have a second part of this to post, and a third part still to write. It's a shame that Narcissa feared being blasted from her family tapestry that she couldn't follow her heart. But then Draco wouldn't have been born.