Metallica fans have long wondered how differently the band might have proceeded if Dave Mustaine hadn't been fired in 1983. The world will never know the answer to that question for sure, but thanks to the Megatallica project, we can kind of get an idea.

Part of a series of mash-ups from YouTube user TheTaskmaster, Megatallica restores this long-sundered creative union by reaching into the vaults and splicing together Metallica tracks with songs recorded by Megadeth, the legendary metal band Mustaine founded after being shown the door. As you might expect, the results are quite loud.

You can listen to the most recent installment, which mashes up Megadeth's 'In My Darkest Hour' with Metallica's 'Welcome Home (Sanitarium)' to create 'Welcome My Darkest Hour,' in the video above, and visit the Megatallica Facebook page to sample more entries in the series, including tracks such as 'For Whom the Peace Sells' and 'Sweating Sandman.'

In the real world, of course, both bands remain active on their own; Megadeth's most recent release, 2013's 'Super Collider,' broke the Billboard Top 10, and Metallica -- who recently announced a giant onslaught of live albums after being inducted into the Guinness Book of World Records -- are at work on their next studio LP.

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