Frotz warning if Dunbar tries to find Baxter after he leaves

>SHOW REPORT TO DUNBAR
She seems stunned but recovers quickly. "He didn't commit suicide, then?" she
says. "But LoBlo, that's a pill I take for my blood pressure." She pauses. "I
can tell what you're thinking, but I didn't, couldn't have done it. Why should
I? Someone must have taken them, maybe George. He knew I used them."

>ACCUSE DUNBAR
"No! I didn't do it! I've worked for Mr. Robner for years. What possible motive
could I have?" With that, Ms. Dunbar begins to cry and move about the room quite
nervously.
Warning: @get_prop called with object 0 (PC = 162c9) (will ignore further
occurrences)

What happens here is that when you accuse Dunbar after you've shown her the lab report (or shortly afterwards anyway, if you don't accuse her), the game calls `DUNBAR-SEQUENCE´:

<ROUTINE DUNBAR-SEQUENCE ("AUX" (BL <LOC ,BAXTER>))
     <COND (,DUNBAR-ACCUSED <RFALSE>)>
     <COND (<NOT <IN? ,DUNBAR .BL>>
        <ESTABLISH-GOAL ,DUNBAR .BL T>)>
     <SETG DUNBAR-ACCUSED T>
     <SETG D-S-BAXTER-LOC .BL>
     <ENABLE <QUEUE I-DUNBAR-SEQ -1>>>

So it tries to make Dunbar walk to Baxter's location. ESTABLISH-GOAL checks the LINE property of both the current location and the destination. That's where the warning is triggered, because the destination is 0.

ESTABLISH-GOAL should probably return immediately if GOAL is 0.

the-infocom-files / deadline

Frotz warning if Dunbar tries to find Baxter after he leaves #63