Alaska (above) is cold. But the governor's race is heating up. (Jason Samenow/The Washington Post)

This post was updated at 5:51 p.m. to reflect Mallott and Walker officially announcing their plans Tuesday afternoon. 

The Alaska governor's race probably hasn't been on your list of must-follows for the fall. But as of right now, it should be.

In short: the Democratic nominee and an independent candidate are teaming up for a unity campaign bent on unseating Gov. Sean Parnell (R). Below is everything we know about what's happened and what's next.

So how is this unity ticket coming together, exactly? 

Democratic nominee Byron Mallott ended his bid to join the ticket of independent Bill Walker, the two announced Tuesday. Under the arrangement, Walker will continue running for governor and Mallott would run for lieutenant governor as his running mate. The state Democratic Party overwhelmingly signed off on the arrangement Monday.

Why do Democrats want this? 

To give themselves the best chance of unseating Parnell. Three-way races are tricky to navigate and they often play to the benefit of the incumbent, who is typically the best-known candidate -- and they often result in unexpected outcomes. (For instance, that's how controversial Maine Gov. Paul LePage (R) got elected in 2010 -- and it's one reason he may be able to hold on to his seat this time around.) With Mallott running as a Democrat, Walker waging an independent campaign and Parnell on the ballot as the Republican incumbent, the governor would have stood a good chance of winning another term. This way, Walker and Mallott -- who, by the way, are friendly with one another -- can try to unite the anti-Parnell vote instead of see it splinter.

What are the potential downsides?

There could be some resentment among Democratic voters that the party decided to play second banana to Walker, who has affiliated himself with the Republican Party. (Walker is ending that affiliation. Mallott, meanwhile, will remain a Democrat.) And Parnell might be able to use the widespread attention on the unity maneuverings to rally the GOP base. He can go to conservative voters and say, 'Hey, look at all the wheeling and dealing opposition is doing to try to remove one of your own from power.'

How vulnerable is Parnell?

Vulnerable enough that Democrats think the unity ticket is a worthwhile gambit. A recent survey from Democratic pollster Public Policy Polling showed Parnell leading a three-way race with 37 percent of the vote -- hardly safe territory for the incumbent. Democrats say the state budget's transition from surplus to deficit in recent years has made Parnell a real target.

Isn't there already another competitive race in Alaska?

Yes! The showdown between Sen. Mark Begich (D) and former attorney general Dan Sullivan (R) is a key contest in the battle for the Senate majority. Outside groups are pouring in big money into the race, which polls show is competitive.

Will the governor's race have any effect on the Senate race? 

It's hard to say. It could motivate more voters to turn out in November. If the governor's race is close, that could mean stronger turnout on both sides, which would be a wash for Begich and Sullivan. But never underestimate a campaign's ability to use all the tools at its disposal to try for a favorable outcome. If meddling in the governor's race or trying to link the opponent to one of the candidates in that contest seems like a smart strategy for either Begich or Sullivan, you can count on them trying it.