Metro: Last Light's second piece of DLC, The Tower Pack, is arriving on 3rd September on Steam, Xbox Live and North America's PSN. European PS3 owners will get it the following day.
Priced at £3.99 / €4.99 / $4.99 - and included in the Season Pass - the Tower Pack is a score-attack challenge mode that tasks players with ascending a giant, well, tower, in a virtual combat simulator so they can compete on the leaderboards. I don't recall there being much advanced technology in 4A Games' incredibly bleak post-apocalypse, but it's the future, so I'll go with it. It doesn't sound as if it will be a very narrative-heavy outing at any rate.
Looking ahead, 4A Games and publisher Deep Silver have two more expansions on the way. The Developer Pack will feature a shooting gallery, Metro Museum, an AI arena, and an additional mission entitled The Spider's Nest.
Lastly, the saga will conclude with the Chronicles Pack, which transpires over three missions, each starring a different set of side characters such as Pavel, Khan & Ulman, and Anna.