Seth Moulton comes to his Senses..

And announces he is not going to challenge Ed Markey for the Senate Nomination in 2020.

Well, thats good news, but it doesn't give us much indication as to Mouton's next move politically.  If he stays in the US House he probably needs to patch things up with Speaker Designate Nancy Pelosi, who so far seems to have picked off most of his insurgent backers without having to come to terms with Moulton himself.  Moreover, he may have to fend off a primary challenge of his own in 2020, likely an ambitious female on the Ayanna Pressley who'll be the distaff embodiment of Mouton's mantra "only by challenge, shall I rise".
Or he could run for President, but literally that depends on Warren not running for President in 2020, and that seems very unlikely.
Lastly The Congressman could want to run for Governor in 2022, that however depends on Baker stepping down after two terms. If Baker does vacate the corner office it's got to look like a competitive race against Karyn Polito in the General Election.  The prime attractant under this scenario is the Bay State's lingering sexism might work in Moulton's favor in a two way match up against the Lt. Governor, said sexism is simply washed in a Polito v. Healey contest.
So may shards ashift in the kaleidoscope...