keach: in a test pit, the team looks for buried structures. do still more houses lie beneath the sugar cane ? after days of digging, the test pit is three meters deep. the workers have found a large piece of wood. it may be the remains of a roof timber. ¿qué han encontrado? ahí está. ¿en la esquina? no. eso no. acá. aquí está. ahí. iotro grande! keach: using the test pit method, the team finds evidence of at least seven buried structures. right there. keach: full excavation begins. slowly, meticulously, the team begins to remove the volcanic ash. weeks later, the ancient floors emerge, yielding the first clues of how these rooms were used. so, anyway, we're really glad to find this. it's certainly not any one of your super-elegant, towering pyramids like at tikal, but, for our purposes, super important to know where they actually did their cooking. and they've got round-bottom pots. and what they'd do is they'd rest one of those round-bottom pots on the three points of contact and put the firewood in from the side. the people in the area still

keach: it took nearly 4,000 years. but around 3500 b.c., in a culture known as sumer, the world's first cities emerged. now, a more complex economy required more complex record-keeping. accountants took a ball of clay which they poked inside with the fingers to make a cavity. you know, it's just like a tennis ball of clay or even smaller. and once they had a good cavity, they would put inside tokens, and then a flap would be put on top, and all of this was closed. and we are in pre-writing time. and at that time every sumerian had a seal. and when the stone is pressed onto the surface of the envelope, it leaves then a design which is then the mark of the person or the administration involved. keach: with these seals, up to four parties could sign a transaction. these envelopes could hold several tokens securely. but there was no way to know the contents until accountants began to press the tokens into the clay before dropping them inside. the system quickly evolved. it did not take a long time for these accountants to

with states he -- stacy keach, i had to punch him.e was on the program and he talked about that. >> the terrifying thing is thinking i would actually connect with him. i am a peaceful person. i played football and that was the extent of my physical experience. i have never punched anybody. i guess i punched my sister in the arm as a youngster. never as a grown man punched my sister. there is the stuntman who is teaching us how to make it look like i am throwing a punch. ify block it in such a way the camera is behind you they show you where to through it so it looks like it is connecting. they block it out from four feet away and when it came time to do it for the cameras, we were about two feet away. i was scared my arm would connect and i would with his face. looking back it would have done way more damage to my hand. he is a man. tavis: he is a big guy. what has the experience done for you in terms of your future as a thespian? the chops are there. >> debatable. tavis: has the dramatic bug officially bitten you now? >> what an expe

i know that once i lifted this heavy [ bleep ] it keachs keep and shrinking and it eventually goes awayst kills itself. >>> many people have all sorts of occupational hazards in their jobs, every day, right? well, be thankful that you don't have this occupational hazard. we've seen this before. as you may recall we did have one video from back in november. >> yes. >> that was one of the most popular videos on our website. a different exploding whale. here we go again. this is in denmark. we've got two beached sperm whales. these whales beached and are dead. they're performing an autopsy. that is a blast of whale blood and guts directly to the face. of course, the bunch of trapped gas that's in there and they have to release this pressure and sort of cause this explosion because this can be a hazard. >> what bothers me is they are not prepared for a blubler blbl blowout. we've seen it before and they've probably done it before, they know it has gas accumulation. >> what should they do? >> a face mask! he should have worn a face mask. but we got to give them for technical expertise, every

. >>> still ahead, a doctor who doesn't believe in keach ieping personal and professional lives separatehow this bay area doctor is going above and beyond for her patients. weights. four hours on the slopes. and two hours doing this stuff. which leaves me approximately two minutes to get my banking done. so i use the citi mobile app to quickly check my accounts and pay my bills. which leaves me about five seconds to kick back. that was nice. bank from almost anywhere with the citi mobile app. citi, with you every step of the way. >>> a lot of people consider a doctor who makes house calls as the epitome of personal service but one oakland doctor may have you rethinking that. garvin thomas shows us just what she is doing in this morning's "bay area proud." >> reporter: bringing work home from the job regardless of what you do is something most of us try to avoid. even more so when you're a doctor. like caroline hastings. >> it's a constant struggle for physicians to find what people refer to as a work/life balance because it is not only just time consuming but it consumes us emotionally a