Update, Dec. 11, 2017: This post has been updated to include campaign finance filings filed with the FEC through Dec. 10.

A special U.S. Senate election in deep-red Alabama — where President Donald Trump prevailed over Democrat Hillary Clinton in 2016 by nearly 30 percentage points — has become unexpectedly close, earning tens of millions of dollars in spending, as well as the attention of the media, major political players and party activists hoping to send a message to Washington.

On Tuesday, former Alabama Supreme Court Chief Justice Roy Moore — whose candidacy has been rocked by accusations of sexual misconduct against teenage girls — faces off against Democrat Doug Jones, a former U.S. attorney. Moore previously defeated incumbent Sen. Luther Strange — who was endorsed by Senate Majority Leader Mitch McConnell (R-KY) — in a GOP primary earlier this fall.

While candidates are limited in how much money they can accept from any single individual donor, super PACs and “dark money” groups have no limits on how much money they can accept from donors or how much they can spend. These groups’ main limitation is that they cannot legally coordinate their spending with the candidates they support.

Next week’s special election was triggered when Trump tapped then-Sen. Jeff Sessions of Alabama to be his attorney general earlier this year.

Here’s what you need to know about the money in the race so far:

$42.7 million is the combined amount that all candidates and political groups have invested so far in the special U.S. election in Alabama, including the earlier primary and primary runoff phases of the election. With spending continuing through Tuesday, that figure could rise even higher.

Voters cast their ballots Tuesday in Alabama's special Senate race. More than $42.7 million has been pumped into #ALSEN race. @IssueOneReform highlights what you need to know https://t.co/Q2BNZnb31N pic.twitter.com/iCa1wRcEPd — Michael Beckel (@mjbeckel) December 11, 2017

$11.8 million is the amount of campaign cash raised by Democrat Doug Jones, who has raised more than $10 million since Oct. 1.

$5.3 million is the amount of campaign cash raised by Republican Roy Moore, who has raised about $2 million since Oct. 1.

$6.7 million is the amount of money super PACs, “dark money” groups and other politically active groups have spent on ads during the special general election phase of the Alabama Senate race, a figure that could increase even more by Election Day.

63 percent is the portion of advertising by outside groups in the special general election phase that has been negative.

2-to-1 is the approximate ratio by which pro-Jones outside groups have outspent pro-Moore outside groups during the special general election phase of the Alabama Senate race.

100 percent is the portion of pro-Jones super PAC Highway 31’s spending — at $4.1 million and counting — that has come from unknown donors. The group won’t report its funders until after the election.

100 percent is the portion of pro-Moore nonprofit Great America Alliance’s spending — $290,00, including $140,000 during the special general election phase of the race — that has come from unknown donors. As a 501(c)(4) nonprofit, the group will never be required to publicly disclose its funders.

55 percent is the portion of Democrat Doug Jones’s campaign war chest that has been raised from small-dollar donors giving $200 or less.

43 percent is the portion of Republican Roy Moore’s campaign war chest that has been raised from small-dollar donors giving $200 or less.

$8 million is the amount of money the Senate Leadership Fund — a super PAC aligned with Senate Majority Leader Mitch McConnell (R-KY) — spent during the GOP primary and primary runoff elections in Alabama unsuccessfully attempting to boost Sen. Luther Strange.

$0 is the amount of money the Senate Leadership Fund has spent boosting Republican Roy Moore since Moore bested Strange in September’s GOP primary runoff election.

Source: Issue One analysis of Federal Election Commission data.