Q Light Controller+

Hi,
Newbie alert with QLC software. I want to make some fun lighting and smoke for haloween. I want to achieve following ind this specific order :

1. Set the lights to specific scene (start of the day)
2. Externally (using the API) i will trigger a sequence (when some movement happens) which will strobe the lights and start the fog machine and this will take few seconds.
3. When the sequence is done i want to go back to 1. and stay there until i trigger again.

I know how to trigger externally, i got that working fine but since i don't know when the sequence is done i don't know when to go back to 1. How can i achieve that ?

You can use a chaser.
The first step of the chaser will be the initial lights setup(scene). The second step will bi another scene that flash the lights and start the fog machine, set the time duration of this step to xx seconds or wathever. When the second step is finished after x seconds the chaser returns to first step of chaser.
In the virtual console put a cue list widget configure with the chaser you early created and assign some external controls to start the chaser via cue list widget. Configure the cue list widget to advance to the second step when movement is detected, when the second step is finished it will return to the first step and when other move detection occurs the second step is triggered.
Take a look to the QLC+ documentation how create a chaser and how create a cue list in the virtual console, learn how to interact with external controls as well.