[sblock=OOC]I really like the idea of Silja and Isobet rescuing Di while searching for the book. The timing is not particulary important to me but it would be preferable if the group (Di, Isobet, Silja) has been together for about a year or so. Since Isobet's background describes her and Vyncent's relationship over a period of years, which implies that Isobet has been around the courtly circles for that same length of time, I would guess that this should fit with her background.
This would allow for Di, Silja and Isobet to have worked as a team for some time (about 1 year) and know each other fairly well. Perhaps most, if not all, of the work that they have done together has been mercenary work, work that requires discretion, for various nobles.
Finally in the case of the fourth person ... well we would need to see both the character and their background first before integrating them into the story, but obviously it would be good if they had skills or interests that aligned with the rest of the group while providing skills or abilities that the group currently does not have.
If the background ideas above suit you guys then I will add it into Di's background.[/sblock]