Quick question on "rounds"

By infinihedron, in Horus Heresy

Having just read the rules for this beautiful monster I did come across one point I'd like to have clarified:

Does a "round" consist of the active player taking only one action then move on to the next "round?"

That was the impression I got from my (so far) one read-through.

I would understand the rules in the same way.

Have a look at the rules page 14, where a round is defined:

"The current player – that is, the player said to have initiative – does not change during a round. The identity of the current player is only determined at the beginning of a round.

In each round, the following steps are carried out:

1. ACTION STEP
2. ADVANCE INITIATIVE MARKER STEP
3. CHANGE OF INITIATIVE STEP (IF NECESSARY)
4. RESOLVE SPECIAL PHASES STEP (IF NECESSARY)

A new round begins immediately when the previous round is completed."

So if you want a round that only consists of one action and nothing else, that's possible, if the current player decides to execute a zero-cost order from his hand (as that'd mean step 2 has no effect, and steps 3 and 4 are skipped). Either way, every new action also means the start of a new round, whether it's carried out by the same player as the last one or the opponent.