You've had a week with Metro: Last Light now and perhaps finished it, so what next? You hardly need me to tell you it's getting DLC, but now it's all properly official and everything. Publisher Deep Silver today announced four add-ons are coming over the summer, including new single-player stories. They'll be covered by a $15 season pass.

The first DLC release will be the Faction Pack in June, which Deep Silver says will bring "new, original single-player gameplay that expands on the Metro: Last Light universe and story." That's the aim of the Chronicles Pack too, which is yet unscheduled.

If you fancy something a little different, the Tower Pack is said to "present a unique solo challenge to Metro veterans" so perhaps some challenge mode sort of thing.

The other DLC, the Developer Pack, is a bit of an enigma, said to "give creative players some interesting tools with which to explore the world of Metro." Some weird tools and modes used in testing to muck around and make odd things happen in-game, one might guess?

The season pass also includes a bonus semi-automatic shotgun rifle which can fire six shells at once.

If you really, positively must buy the season pass right away even though the first DLC isn't coming until June, it's already in the Xbox Live Marketplace and is due on PC and PlayStation 3 today too. PS Plus members will get a 25% discount until June 4. With a $15 price and the usual discount for buying in bulk with a pass, one imagines the DLC packs will come to at $20 or so bought individually, but Deep Silver doesn't say.