I'm not good in english, but:
1) at first
{set-var hp 5}
we need to set some "HP" variable, on "world" script
2) At enemy/danger sprite:
{dec-var hp 1} {if {lte {var hp} 0}} {move-avatar start 3 3} {/if}
* (1-st line) "dec-var" - it's like "hp - 1" ("dec-var" - decrease variable)
* (2-nd line) lte - it's like "if (hp <= 0)" ("lte" - low then or equal)
* (3-rd line) move-avatar to level with name "start" on X,Y axis (we need have "start" level and don't have any walls on 3,3 axis)
* (4-rd line) if ending state
I hope I don't make errors here!