Rainbow Six Siege [official site] is a game about breaching into factories and planes and houses and clearing out the terrorists who wait inside. Its closed beta, meanwhile, is like the terrorists instead; it's come to visit and now it won't leave. It launched on September 24th and now it's been extended through till October 4th.
Aside from giving you more time to play, an update on the Rainbow Six Siege site also explains that anyone who played the beta before September 29th will have an extra code for the closed beta that they can share with a friend. This is the beta's second extension, the first extension having taken the beta up until today.
I wonder if this means the game is struggling to get player numbers, which would be a shame. I played an earlier beta back in May and enjoyed it a lot, and this new beta includes a new version of Terrorist Hunt, a co-op mode that was great to play with friends in the Rainbow Six Vegas games.
Siege is due for release on December 1st. Here's the closed beta trailer in case you missed it last time.