After doing 'Firefly' and moving on I always wanted to be part of a series again. I love doing films too but there's just something special about being part of the team and feeling like you're actually a part of the family and I always look to re-create that.
To make a love story you need a couple of young people but to reflect on the nature of love you're better off with old ones. That is a fact of life and literature - and of the novel ever since it fell in love with love in the 18th century.