"American Experience: Two Days in October," 9 p.m., PBS. In October 1967, Americans assumed life was still serene. There was peace at home and a winnable war in Vietnam. That changed with two confrontations: On Oct. 17, a special unit met a Viet Cong ambush; almost half the 142 Americans were killed, a number of others were wounded. On Oct. 18, police and protesters collided at the University of Wisconsin; 65 people were hospitalized. Those parallel stories were told in David Maraniss' book, "They Marched Into Sunlight." They are retold here with rich detail. Clark Welch, a rock-solid infantry officer, describes rallying his troops and watching his commanding officer die. Nguyen Van Lam, a Viet Cong soldier, describes the corpse-filled battleground. "What we saw made us shudder." He now farms that same field. At UW, Jane Brotman was a freshman and viewed the violent acts on campus. "It was the most brutal and violent thing I have ever witnessed," she says. She became a protester, too. American life had changed.

OF NOTE

"Surface," 7 p.m., NBC. The boys really shouldn't be secretly keeping a baby creature at home. Now the neighbor's dog is missing, and they're being questioned.

"How I Met Your Mother," 7:30 p.m., CBS. Ted and Barney get to go with Robin to a VIP spot at a nightclub. Marshall and Lily — the cheery, engaged couple — host a wine-tasting party.

"Two and a Half Men," 8 p.m., CBS. Here are uncharacteristic moments for both brothers: Charlie is impotent; Alan is asked (by his son) for advice about girls.

"CSI: Miami," 9 p.m., CBS. Desperate housewives turn deadly? A hotel pool boy had been having affairs with three women. Now he's been killed.

"Medium," 9 p.m., NBC. Allison dreams of a former friend she hasn't seen since they were teens.