my dad's second-last puzzle

Today being father’s day, I’d like to recall a puzzle my late dad gave me in June 1998 a couple of weeks before he had a fatal series of cardiac arrests. Of course I’ve come across this plenty of times later as well… I suppose it must be fairly well known by now. I must confess that I couldn’t solve it though I tried for quite a while, and then finally bugged him till he relented and gave me the answer.

But anyway if you haven’t seen it earlier, try to attempt it – dosen’t matter if you don’t succeed but try as much as possible, its implications could turn out to be quite pathbreaking.

**the puzzle:**
Consider the 9 dots below – they need to be joined with *four consecutive* (without lifting pen) straight lines.

* * *

* * *

* * *

—-

His *last* puzzle however was his abrupt departure itself …and for that I didn’t have the choice of giving up and asking him at all… 🙂 its something to figure out myself – though I believe this gives one a better sense of satisfaction! I must say his second-last puzzle is of much help in the attempt to solve his final one.