I will keep this short and sweet, much like your preferred method of communication.
This is but one little birthday present from yours truly. There is another on the way and I imagine you'll be overjoyed when this gift of mine arrives.
Happy Birthday, Darling!
All my love, Delphine
[Attached is a medium-sized parcel wrapped in cheerful paper and tied with a bow. Inside is an item of your choice, from Marcus's past or future, but something that did not belong to him at the moment of his departure for Elysium. It cannot be one of his baggage items.]