Exploratory Cartographer was awarded to me after completing āThe Future is Nowā post-patch. I didnāt even complete the mission with Successful or Outstanding! Nope, just needed to have finished the mission.
Observing the Impossible achievement is likely The Fungoid Mystery -> The Horror in Fungus.
Maybe tomorrowās patch will include something new to continue the chain!
There are several new T5 agent missions now. A cabal mate has them. One gives a map as a reward and he hasnāt figured out where to use it, yet. Using it says āYou are not in the right locationā or whatever the exact wording isā¦ hmmmā¦
He didnāt get the mission details, so Iāll still need someone to post them, please.
I havenāt seen any new T5 missions yet. Has he done all the prior Jeronimo chain?
I wonder if it is just RNG, or if there is maybe some other pre-requisite Iām missing. Time will tell I guess.
Edit: There are a number of T5 quests I havenāt completed yet, so I guess it is possible new ones could be continuations of old lines.
Yes, he had finished all previous Jeronimo missions. He named 3 different missions and I donāt remember their names now. The plot centers around Dark Agartha.
He linked us in chat the map that he got from the first mission. Itās an actual inventory item. He was talking about something from the third mission that required an oustanding result to get, but I didnāt catch what he was talking about. It was over voice chat in Discord and I was incredibly busy with something else at the time and missed it.
DARK AGARTHA?
DARK!!!
AGARTHA!!!
Dark Agartha in JerĆ³nimoās chain and a mysterious map and possibly more items all related to DARK AGARTHA?!
WE NEED TO KNOW MORE
My first theory 
Finally! After days of doing missions, a few Iād never done before in T4 and T5, my first Dark Agartha Mission has arrived!
Only doable by Jeronimo.
Into Dark Agartha
T5, 1 hour
Rewards: Weapon and Glyph Distillates - 600CC
Bonus Objective 300CC Weapon Distillate
OOMMMMGGGGGGG 
I wonder why the Bonus Objective requires Resilience trait, a quality JerĆ³nimo de Montejo does not possess.
Well, there are items which grant you an extra trait. I have never got one though. Funny that they would do that though. It isnāt like the bonus reward is any good.
The Conquistadorās Secrets - T5 - 15min
150-1500 Anima Shards
Crudely Drawn Map
Weapon Distillate (600cc)
Bonus Objective (supernatural): Glyph Distillate (300cc)
Edit: Added Bonus Objective
After talking to some people it seems like you might need to redo the final T4 Jeronimo mission to trigger the new T5 missions to appear.
EDIT: I also have a total of 5 missions for the new chain. Iāll post the info shortly.
EDIT2:
Final EDIT: I donāt have mission text for these missions (these are from a cabal mate). Weāre also not sure what those items are used for. Clearly theyāre going to be used somewhere, butā¦ where and for what? Will we get to go to Dark Agartha for some mission? It would be neat if the Agent system actually had some impact outside of itself. Right now, itās mostly self contained. I toss out almost all of the distillates I get (anything 500xp and under). The Mushroom Coated Hagstone as the final reward (or what I assume to be the final reward. I donāt know if there is a 6th mission or not) might imply that you use them in Stonehenge, maybe? Or somethingā¦ who knows. I trust this community to figure it out. 
Meanwhile Iām over here waiting for āThe Hidden Expeditionā to show upā¦ RNG once per several hours is bad
I think they did make the Jeronimo-only T4s stop showing up until you finish the 2nd chain though, I havenāt noticed āOnce Again into Agarthaā in a bit.
Iām not positive on this one. I regrettably havenāt kept track of times I do missions, just which ones Iāve done and on whom. I donāt think I re-did that mission that recently, but it is possible since it was on an agent I havenāt been using much.
Thanks for that suggestion. Gonna try that out cause I have done all but the last chain and it hasnt shown up for a week now in Tier 5 ill update if that works.
I swear Funcom would have made a killing off of mission refresh for aurum lol
Three people in my cabal said that they got them after they started redoing some of the T4 missions, so thatās the logical conclusion. Of course, it could always be something else.
Iām still here waiting for Mysteries of the Sphere to show up so that I can finish the T3 chain. 
