The fate of two universes hang in the balance. The alternate Walter Bishop, Secretary for Defence, wants to destroy the prime universe to ensure the continued survival of his own. To this end he has imprisoned Olivia Dunham and set her alternate counterpart to infiltrate her team and help in this cause. Trapped in the parallel universe, Olivia needs to escape back to her own world.
The third season of Fringe picks up shortly after the previous season's finale and establishes a new format. For the first few episodes of the season it alternates between the parallel universe and the prime one, with the opening title sequence changing colour depending on which is the focus of each episode. This is a smart move, establishing the parallel universe and its characters in more depth. The writers, directors and actors work extremely hard to ensure the alternate world is convincing, and by setting entire episodes there (even a stand-alone mystery episode) they manage to pull it off. The devil is in the details and these details - the still-standing twin towers, people keeping badgers as pets, sheep being extinct, everyone using bluetooth headsets, the Statue of Liberty still having its bronze covering - are finely-judged.
The show does go through a mid-season patch when, with the opening situation rectified, it falls back on its more traditional mystery-of-the-week storylines. However, the show remains inventive and entertaining even when dealing with what might have easily descended into filler. An episode set in the parallel universe dealing with people who are consumed by parasites is Fringe at its most queasily effective; an episode featuring Walter bonding with an aged rock star played by Christopher Lloyd is both geek-pleasing and superbly-acted (John Noble, of course, is on top form throughout the season). Best of all in this set of episodes may be an instalment set in an apartment block gripped by strange events which appears to be a stand-alone case but eventually dovetails rather nicely into the main, ongoing storyline.
Later episodes in the season take an unexpected turn for the predictable: a storyline where 'our' Olivia is possessed by another character strains even Fringe's elastic notions of credulity (despite Anna Torv's superb performance), whilst a regular character getting pregnant and thus causing drama may tax the patience of many viewers. However, there are upsides even to these storylines: the possession storyline leads to an episode that unfolds mostly in animation and is the show's craziest and most inventive hour to date, whilst the pregnancy storyline turns out to not quite be as critical as it initially appears. The concluding three-episode arc resolves the season-spanning story arc quite effectively, as well as negating a potentially cheesy background element and ending things on a startling cliffhanger that leaves the show able to make a fresh start in the fourth season.
The third season of Fringe (****½) strains credulity a bit more than the second season and by the end has taken so many twists and turns you may regret not taking notes. However, the cast is as excellent as ever (Anna Torv stepping up to the plate with multiple versions of Olivia is particularly noteworthy), the plotting is assured and the show's mix of tragedy, action and light comedy is as satisfying as ever. The season is available now in the UK (DVD, Blu-Ray) and USA (DVD, Blu-Ray).