This is Rumour Control. Here are... some rumours. MarketSaw, a blog focused on all things 3D, has heard from a "trusted source" in the Hobbit camp that a hitherto unmentioned third instalment is in the works.

Mr. Reliable's exact words are apparently that "I'm hearing, and it's only speculation at the moment, that it will be three [films]... I hear this from lots of people and have seen things to indicate this may be the way it's heading: Del Toro on Hobbit duty and Jackson on the 'bridge' project. Time will tell."

Time will tell indeed. El Reliablo also claims that Jackson is keen on 3D, whilst Del Toro is holding back, which does at least chime with some previous reports.

But if splitting The Hobbit across two films was already intended to allow breathing space for the inclusion of expanded Middle Earth material from Tolkien's copious Lord of the Rings appendices and The Silmarillion, what would a third film achieve? Surely there's no need for a 'bridge' between The Hobbit and The Lord of the Rings: we've seen all we need to see. We know where the One Ring was in the intervening years.

We can think of the story of the five wizards (Saruman and Gandalf among them) sent by the Valar to resist Sauron, but by rights that predates the events of The Hobbit. Or there's the issue of Sauron's development from The Hobbit's briefly mentioned Necromancer of Mirkwood into the Big Fiery Eye we know and love. But that's seriously esoteric stuff, and it's hard to see quite how it could form the basis for a special FX 3D blockbuster extravaganza.

Sounds decidedly fishy to us (so Gollum at least might be excited by it), but what do you think? Can any of the Tolkien experts out there think of a way to carve The Hobbit into three, without it outstaying its welcome?