The Dink Network

Use say_stop instead of say_stop_npc. You'll rarely need say_stop_npc, that's when you want to have a NPC talking in the background where Dink doesn't interfere with the conversation: ie, they talk in the background and Dink does other things, pressing spacebar won't change the NPC's conversation.

Edit: more importantly, change the sp_touch_damage of the blocker to sp_touch_damage(&current_sprite, 0); before the whole code and back to -1 after the whole code. Because you freeze Dink when touching the sprite, it'll constantly trigger this script so it'll crash Dink. Also, the kill_this_task(); code doesn't seem necessary to me in a blocker script because you'd want the blocker to function every time Dink touches it.