The Chrono-Corp began existence as an elite military force during The Last War of the future of Sax And Violins (the timestream you reading this currently reside within), but the name may be familiar to those of you who Sidestep from one timestream to another or just use time dilation devices to travel forward or backward within the streams.
The Chrono-Corps remained for decades after the war and began to change focus to monitoring the streams and patrolling the past to locate Tempus Fugitives.
The influence of the Corps spread slowly across the streams, and they eventually discovered the prime stream and set up base deeper into the past than anyone had ever traveled before, essentially extending their reach into every alternate world and period of history that has ever existed. They have since then blocked off that stream from public knowledge, essentially creating a safe haven for them to retreat to in case of emergency.
The group now remains as a phantom only, erasing themselves from memory after each incursion, so that they have transformed into a mysterious force beyond reach.
This is a rarely found hatpin worn by one of the crew of Primebase Omega-Alpha. Artifacts like this are not meant to exist according to their own laws, so it must have fallen into a certain dimensional importer's possession though 'unfortunate circumstances'.
Caveat emptor. It is only a matter of time (ha!) before one of their agents will arrive to retrieve this item. Could be a century, could be a week...