er dahintersteckt

is behind it, is responsible for it

→ dahinterstecken
da of the + hinter behind + steck to be stuck, be lodged + t 3rd-person singular present
verb · 3rd-person singular, present tense Rare #40,695
is behind it, is responsible for it Often used when asking or saying who or what is secretly causing or motivating something.
GE: Ich weiß nicht, wer dahintersteckt.
EN: I don’t know who’s behind it.

Es gibt da natürlich jemanden, der möglicherweise dahintersteckt.

There is obviously someone who might be behind it.

— Harry Potter und der Orden des Phönix (2007)

Sie meinen, was dahintersteckt?

You mean, what’s behind it?

— Fitzcarraldo (1982)

Wir werden nie erfahren, wer dahintersteckt.

We'll never find out who's behind it.

— James Bond 007 - Casino Royale (2006)

Keine Ahnung, welche Magie dahintersteckt.

No idea what kind of magic is behind it.

— The Garden of Sinners: Paradoxe Helix (2008)

Ich werde nicht mehr sagen, dass die Nation of Islam dahintersteckt.

I will no longer say that the Nation of Islam is behind it.

— Malcolm X (1992)