Meaning of 後に in 研究員たちが後に続くと、博士は笑みを浮かべた。

Question

I'd like to confirm if the 後に in

研究員たちが後に続くと、博士は笑みを浮かべた。

is referring to sometime later. In other words, if the sentence can be translated as

When the researchers followed later on, the Professor showed a smile on its face.

Additionally, what is the function of に in this case? I don't think it's a temporal marker since relative time expressions (e.g. 明日, 今日...) do not take に. My guess is that 後に is an adverb modifying 続く, but I'd like to check.

Finally, this was taken from a Pokemon light novel. For context, a group of researchers has found a lithograph inside some ruins and are discussing the engraving. With this in mind, I'm also wondering if this 続く could refer to their talk instead.

I've included the excerpt below:

ジャングルの中で博士たちを見ていた、ピンク色のポケモン。
「ミュウです」
発掘隊員が石版を指すと、博士は感嘆の表情を浮かべた。
「神秘の力を持ち、大洪水を引き起こしたとか••••••荒地に作物を実らせ、人々に分け与えたとか••••••」
「天使か悪魔か」
「気まぐれなだけか」
研究員たちが後に続くと、博士は笑みを浮かべた。

Answer 1

This 研究員たちが後に続いた means "The researchers followed (by saying 天使か悪魔か/気まぐれなだけか)" or "The researchers continued the doctor's statement" in this context. This 後 refers to the end of the 博士's statement (神秘の力を...).

This に is merely a particle commonly used with 続く. Unlike follow in English, 続く is intransitive and you need に instead of を (see this for similar examples).

春に続いて夏がやってきた。
Summer has come following spring.

"Later on" is 後で. See: に vs で again: 前に vs 後で