Childish Gambino may have given his new mixtape, 'STN MTN,' away for free, but the rapper made fans work extra hard to hear a secret track from his new EP, 'Kauai.'

One look at the effort's tracklist details a song reminiscent of his 2013 hit '3005,' 'V. 3005 (Beach Picnic Version),' which serves as the very last track. His loyal supporters probably thought they were just getting a remixed instrumental of the original version but turns out there was an a cappella to go along with it.

The rap hunt began and though he didn't give any clues as to where to find the a cappella, one fan did. Reddit user peepsie112 unlocked the lyrical treasure and as a result, was given a nod of approval by Gambino on Twitter.

"People keep asking how I found it, so I'll try and explain," the Reddit user wrote. "new audioObject('30059','12zzQ809',234) is a line of code used to play 3005 on the because the internet script, '12zzQ809' is the song id or file name, so instead of using '12zzQ809', I just replaced it with lemongrab because above the secret track section it says '[LEMONGRAB: UNNACCEPTABLE!]', nothing too special really."

"See me out in my ride, want to key it up / You gotta Kia / I got a Beema / She got a Fiat, half Italian / She want a ride up, I'ma stallion," he rhymes on the mellow groove.

'Kauai,' which leaked before its release date, is now available on iTunes and features collaborations with Jaden Smith and Christian Rich.

Listen to Childish Gambino's '3005 Pt. 2'

See 20 Rappers' Real Names Revealed