It doesn't get any easier! New stills show heroes set for toughest challenge yet on The Walking Dead Season 3

Say hello to my little friend: Andrew Lincoln's character Rick Grimes is making a comeback in the new series of The Walking Dead

Fans will be especially excited to find out more about the mysterious prison building that was shown at the climax, which is thought to be the setting for season three.It is certainly not a welcoming place if the new stills released today of the survival horror are anything to go by, with many of the images showing them engaged in (un)deadly combat.Meanwhille Andrea, who was separated from the group, has luckily found a powerful new ally

Katana wielding Michonne, who walks around with two zombies she has a special affinity to chained to her, is set to be arguably the most memorable character yet.executive producer Gale Ann Hurd said: 'Michonne kicks a** with a katanna sword. The intensity level is incredible.'We've got our cast inoculated now. The new people realize just what they're in for and the level that we expect.'They've become just as passionate about The Walking Dead as we all are.'A mysterious character called The Governor and scumbag Merle Dixon are also in the mix to add plenty of spice to proceedings.

Fans of the show will have to wait another couple of months to see exactly how the story unfolds.The next season of The Walking Dead premieres October 14, and the producers of have a lot to live up to.The season two finale drew in historical ratings for AMC when it aired back in March.Nine million viewers tuned in for the episode, making it the highest-rated in the series' history with nearly six million of them adults aged 18 to 49.