diff --git a/common/mtime/mtime.go b/common/mtime/mtime.go
new file mode 100644
index 000000000..dd1fc87ca
--- /dev/null
+++ b/common/mtime/mtime.go
@@ -0,0 +1,16 @@
+package mtime
+
+import "time"
+
+// Now returns the current time.
+var Now = func() time.Time { return time.Now() }
+
+// NowForce sets the time returned by Now to t.
+func NowForce(t time.Time) {
+	Now = func() time.Time { return t }
+}
+
+// NowReset makes Now returns the current time again.
+func NowReset() {
+	Now = func() time.Time { return time.Now() }
+}
diff --git a/probe/docker/container.go b/probe/docker/container.go
index 27e581c2b..82c9bcdc9 100644
--- a/probe/docker/container.go
+++ b/probe/docker/container.go
@@ -17,6 +17,7 @@ import (
 
 	docker "github.com/fsouza/go-dockerclient"
 
+	"github.com/weaveworks/scope/common/mtime"
 	"github.com/weaveworks/scope/report"
 )
 
@@ -268,7 +269,7 @@ func (c *container) GetNode(hostID string, localAddrs []net.IP) report.Node {
 		ContainerPorts:         c.ports(localAddrs),
 		ContainerIPs:           report.MakeStringSet(ips...),
 		ContainerIPsWithScopes: report.MakeStringSet(ipsWithScopes...),
-	}).WithLatest(ContainerState, state)
+	}).WithLatest(ContainerState, mtime.Now(), state)
 
 	if c.container.State.Paused {
 		result = result.WithControls(UnpauseContainer)
diff --git a/probe/docker/container_test.go b/probe/docker/container_test.go
index a0dc73deb..a7c60cdd0 100644
--- a/probe/docker/container_test.go
+++ b/probe/docker/container_test.go
@@ -14,6 +14,7 @@ import (
 
 	client "github.com/fsouza/go-dockerclient"
 
+	"github.com/weaveworks/scope/common/mtime"
 	"github.com/weaveworks/scope/probe/docker"
 	"github.com/weaveworks/scope/report"
 	"github.com/weaveworks/scope/test"
@@ -64,6 +65,10 @@ func TestContainer(t *testing.T) {
 		t.Error(err)
 	}
 
+	now := time.Now()
+	mtime.NowForce(now)
+	defer mtime.NowReset()
+
 	// Now see if we go them
 	want := report.MakeNode().WithMetadata(map[string]string{
 		"docker_container_command": " ",
@@ -80,7 +85,7 @@ func TestContainer(t *testing.T) {
 		"docker_container_ips_with_scopes": report.MakeStringSet("scope;1.2.3.4"),
 	}).WithControls(
 		docker.RestartContainer, docker.StopContainer, docker.PauseContainer,
-	).WithLatest("docker_container_state", "running")
+	).WithLatest("docker_container_state", now, "running")
 
 	test.Poll(t, 100*time.Millisecond, want, func() interface{} {
 		node := c.GetNode("scope", []net.IP{})
diff --git a/render/renderable_node.go b/render/renderable_node.go
index eccda8560..8519f3687 100644
--- a/render/renderable_node.go
+++ b/render/renderable_node.go
@@ -134,12 +134,7 @@ func (rn RenderableNode) Copy() RenderableNode {
 // Specifically, that means cutting out parts of the Node.
 func (rn RenderableNode) Prune() RenderableNode {
 	cp := rn.Copy()
-	cp.Node.Metadata = report.Metadata{}     // snip
-	cp.Node.Counters = report.Counters{}     // snip
-	cp.Node.Edges = report.EdgeMetadatas{}   // snip
-	cp.Node.Sets = report.Sets{}             // snip
-	cp.Node.Controls = report.NodeControls{} // snip
-	cp.Node.Latest = report.LatestMap{}      // snip
+	cp.Node = report.MakeNode().WithAdjacent(cp.Node.Adjacency...)
 	return cp
 }
 
diff --git a/report/controls.go b/report/controls.go
index be3e7b92e..bb058939a 100644
--- a/report/controls.go
+++ b/report/controls.go
@@ -2,6 +2,8 @@ package report
 
 import (
 	"time"
+
+	"github.com/weaveworks/scope/common/mtime"
 )
 
 // Controls describe the control tags within the Nodes
@@ -37,18 +39,18 @@ func (cs Controls) AddControl(c Control) {
 	cs[c.ID] = c
 }
 
-// NodeControls represent the individual controls that are valid
-// for a given node at a given point in time.  Its is immutable.
+// NodeControls represent the individual controls that are valid for a given
+// node at a given point in time.  Its is immutable. A zero-value for Timestamp
+// indicated this NodeControls is 'not set'.
 type NodeControls struct {
-	Timestamp int64  `json:"timestamp"`
-	Controls  IDList `json:"controls"`
+	Timestamp time.Time `json:"timestamp"`
+	Controls  StringSet `json:"controls,omitempty"`
 }
 
 // MakeNodeControls makes a new NodeControls
 func MakeNodeControls() NodeControls {
 	return NodeControls{
-		Timestamp: time.Now().Unix(),
-		Controls:  MakeIDList(),
+		Controls: MakeStringSet(),
 	}
 }
 
@@ -60,7 +62,7 @@ func (nc NodeControls) Copy() NodeControls {
 // Merge returns the newest of the two NodeControls; it does not take the union
 // of the valid Controls.
 func (nc NodeControls) Merge(other NodeControls) NodeControls {
-	if other.Timestamp > nc.Timestamp {
+	if nc.Timestamp.Before(other.Timestamp) {
 		return other
 	}
 	return nc
@@ -69,7 +71,7 @@ func (nc NodeControls) Merge(other NodeControls) NodeControls {
 // Add the new control IDs to this NodeControls, producing a fresh NodeControls.
 func (nc NodeControls) Add(ids ...string) NodeControls {
 	return NodeControls{
-		Timestamp: time.Now().Unix(),
+		Timestamp: mtime.Now(),
 		Controls:  nc.Controls.Add(ids...),
 	}
 }
diff --git a/report/latest_map.go b/report/latest_map.go
index a93c90660..97748db8c 100644
--- a/report/latest_map.go
+++ b/report/latest_map.go
@@ -18,8 +18,8 @@ type LatestMap struct {
 
 // LatestEntry represents a timestamped value inside the LatestMap.
 type LatestEntry struct {
-	Timestamp int64  `json:"timestamp"`
-	Value     string `json:"value"`
+	Timestamp time.Time `json:"timestamp"`
+	Value     string    `json:"value"`
 }
 
 func (e LatestEntry) String() string {
@@ -46,7 +46,7 @@ func (m LatestMap) Merge(newer LatestMap) LatestMap {
 
 	m.Map.ForEach(func(key string, olderVal interface{}) {
 		if newerVal, ok := newer.Map.Lookup(key); ok {
-			if olderVal.(LatestEntry).Timestamp > newerVal.(LatestEntry).Timestamp {
+			if newerVal.(LatestEntry).Timestamp.Before(olderVal.(LatestEntry).Timestamp) {
 				output = output.Set(key, olderVal)
 			}
 		} else {
@@ -67,9 +67,8 @@ func (m LatestMap) Lookup(key string) (string, bool) {
 }
 
 // Set the value for the given key.
-func (m LatestMap) Set(key string, value string) LatestMap {
-	now := time.Now()
-	return LatestMap{m.Map.Set(key, LatestEntry{now.Unix(), value})}
+func (m LatestMap) Set(key string, timestamp time.Time, value string) LatestMap {
+	return LatestMap{m.Map.Set(key, LatestEntry{timestamp, value})}
 }
 
 func (m LatestMap) toIntermediate() map[string]LatestEntry {
diff --git a/report/topology.go b/report/topology.go
index 613683a67..9fa6de15c 100644
--- a/report/topology.go
+++ b/report/topology.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"sort"
 	"strings"
+	"time"
 )
 
 // Topology describes a specific view of a network. It consists of nodes and
@@ -140,9 +141,9 @@ func (n Node) WithSets(sets Sets) Node {
 }
 
 // WithAdjacent returns a fresh copy of n, with 'a' added to Adjacency
-func (n Node) WithAdjacent(a string) Node {
+func (n Node) WithAdjacent(a ...string) Node {
 	result := n.Copy()
-	result.Adjacency = result.Adjacency.Add(a)
+	result.Adjacency = result.Adjacency.Add(a...)
 	return result
 }
 
@@ -163,9 +164,9 @@ func (n Node) WithControls(cs ...string) Node {
 }
 
 // WithLatest produces a new Node with k mapped to v in the Latest metadata.
-func (n Node) WithLatest(k, v string) Node {
+func (n Node) WithLatest(k string, ts time.Time, v string) Node {
 	result := n.Copy()
-	result.Latest = result.Latest.Set(k, v)
+	result.Latest = result.Latest.Set(k, ts, v)
 	return result
 }
 
diff --git a/test/fixture/report_fixture.go b/test/fixture/report_fixture.go
index 7bb8f4b92..e0567760e 100644
--- a/test/fixture/report_fixture.go
+++ b/test/fixture/report_fixture.go
@@ -15,6 +15,8 @@ import (
 // This is an example Report:
 //   2 hosts with probes installed - client & server.
 var (
+	Now = time.Now()
+
 	ClientHostID  = "client.hostname.com"
 	ServerHostID  = "server.hostname.com"
 	UnknownHostID = ""
@@ -219,7 +221,7 @@ var (
 					docker.ImageID:                                ClientContainerImageID,
 					report.HostNodeID:                             ClientHostNodeID,
 					docker.LabelPrefix + "io.kubernetes.pod.name": ClientPodID,
-				}).WithLatest(docker.ContainerState, docker.StateRunning),
+				}).WithLatest(docker.ContainerState, Now, docker.StateRunning),
 				ServerContainerNodeID: report.MakeNodeWith(map[string]string{
 					docker.ContainerID:                                      ServerContainerID,
 					docker.ContainerName:                                    "task-name-5-server-aceb93e2f2b797caba01",
@@ -229,7 +231,7 @@ var (
 					docker.LabelPrefix + "foo1":                             "bar1",
 					docker.LabelPrefix + "foo2":                             "bar2",
 					docker.LabelPrefix + "io.kubernetes.pod.name":           ServerPodID,
-				}).WithLatest(docker.ContainerState, docker.StateRunning),
+				}).WithLatest(docker.ContainerState, Now, docker.StateRunning),
 			},
 		},
 		ContainerImage: report.Topology{