This series is set in the Letters to Whistler universe which is about five years into the future of the current (Seasons 3 & beginning of Season 4) BTVS timeline. LFI is a sequel to Letters to Whistler. Buffy and Angel are going to try to be together once he arrives back in the US after a stay in Ireland. Since he's a vampire, the trip takes over a month. During the time while they wait to be reunited, Angel has arranged to send Buffy the letters that he has written to her while he was in Ireland.