Comic collectors, you’re being put on notice; you’ve got less than two years to gather up your Captain Marvel keys.

In 2019, “Captain Marvel” will enter the Marvel Cinematic Universe in style as Carol Danvers will reportedly take on the Skrull invasion, which could set up even bigger things for the MCU.

While Carol Danvers isn’t the only Captain Marvel, she is by far the most popular.

Originally, there was the Kree warrior, Mar-Vell. Danvers initially was known as Ms. Marvel until Mar-Vell bit the proverbial dust in 1982’s “Death of Captain Marvel.” However, she wasn’t christened with the title “Captain Marvel” until 2012. Don’t forget that there’s also a new Ms. Marvel, Kamala Khan, who debuted a year later.

Since Danvers will be the Captain Marvel of the MCU, where should you start with collecting her key issues? I’m glad I asked for you.

MARVEL SUPER-HEROES #13

This is a case of killing two birds with one stone.

In this 1968 silver age classic, readers got their second look at Mar-Vell and, for the astute, they saw the first appearance of Carol Danvers. It’s yet to be revealed if Mar-Vell will or won’t be in the movie, but it’s a safe bet that with all the cosmic storylines in the MCU, he will eventually drop into the movies. That will only make this comic even more in demand.

All that being said, you’ll want to get your hands on this one while you can. However, as serious collectors know, silver age keys in high grade are always costly. In this case, a graded 9.0 went for $1,200 back in May. If you want a mid-grade copy, that price drops significantly and is below $300 at the moment.

MARVEL SUPER-HEROES #12

This is a cheaper option that still has you in the Captain Marvel mythos.

While it’s not as important as “Marvel Super-Heroes” #13, this issue still is a significant key in that it is the debut of Mar-Vell. Back in those days, he wore white and green. By the bronze age, he sported a red and blue uniform that would be the staple of all the versions to follow.

Want an issue of your own? Near-mint graded copies average over $400.

MS. MARVEL #1

If you’re looking to invest in a key comic that will gain value once “Captain Marvel” premieres in 2019, then there’s really only one issue at the top of the list: “MS. MARVEL” #1.

Sure, Carol Danvers made her debut in the aforementioned “Marvel Super-Heroes” #13, but she didn’t gain her superpowers until 1977.

As trailers drop on YouTube and the big day gets closer, this comic will become increasingly popular. Not that it needs any help. “Ms. Marvel” #1 is one of the most commonly sold comics on eBay. In 2017 alone, there have already been 34 sales of copies graded at 9.0. In case you want one of these for your own collection, anything in the near-mint range will cost you anywhere from $120 to $150. Compared to that “MSH” #13, it’s a steal.