Cryptic messages posted online allude to Tool announcing a February, 2020 tour of Australia and New Zealand.
The 'Aenima' rockers, who released their long-awaited fifth album Fear Inoculum this year, have played 10 concerts in Aotearoa - the first in 1997 and the last in 2013.
Frontier Touring has taken to social media with the hashtag #FollowTheEvidenceAUNZ and a message with each word animated, upside down and in the distinctive Fear Inoculum font.
"Perth, Sydney, Brisbane, Melbourne, Auckland, February 2020," it reads.
The posts also contain a link to the Follow The Evidence website, which is running a promotion for social media users to post their own 'clues' and potentially win tickets.
It also has a countdown to the announcement, which finishes 10am next Friday morning (November 15).
Tool has so far played 15 concerts in the US on their Fear Inoculum tour.
A Facebook event entitled 'Bring TOOL to New Zealand 2019' has 4300 registered as 'going' and 10,000 as 'interested', at the time of publishing.
Shortly before Fear Inoculum's release on August 30, Tool's back catalogue was released on streaming services for the first time ever.